title: CSS 2.1 errors: not a known property name
body: <p>Here is my code, I got it from an AJAX sample:</p>
  
  <pre><code>body, div, p, h1, h2, h3, h4, ul, li, table
  {
      margin:0;
      padding:0;
      border:none;
  }
  
  body
  {
      background: #B4B4B4 url(images/body_bg.gif) repeat left top;    
      font-family: Tahoma, Arial, sans-serif;
      font-size:75%;
  }
  
  /* Master Page Layout */
  #master_header
  {
      margin: -1px auto 0 auto;
      width: 800px;
  }
  
  #master_headertop
  {
      background: url(images/headertop_img.jpg) no-repeat left top;
  }
  
  #master_headerbottom
  {
      background: url(images/headerbottom_img.png) no-repeat left top;
  }
  
  #master_page
  {
      margin: 5px auto 20px auto;
      width: 800px;
  }
  
  #master_menu 
  {
      float: left;
      width: 240px;
      padding-right: 10px;
  }
  
  .sidebar 
  {
      width: 100%;
      margin-bottom: 10px;
  }
  
  .sidebarheader
  {
      height: 24px;
      padding: 10px 0 0 35px;
      background: url(images/sidebar_header.png) no-repeat left top;
      color: #FFF;
      font-family: Arial, Sans-Serif;
      font-size: 1.2em;
      font-weight: bold;
      text-transform: uppercase;
  }
  
  .sidebarcontent
  {   
      border: 1px solid #0F2543;
      padding: 20px 20px 20px 30px;
      line-height: 1.5em;
      font-weight: bold;
  }
  
  #master_sidebarSamples
  {   
      padding-top: 72px;
      background: #FFF url(images/samples_bg.gif) no-repeat left top;
  }
  
  #master_sidebarWalkthroughs
  {
      padding-top: 72px;
      background: #FFF url(images/walkthrough_bg.gif) no-repeat left top;
  }
  
  .sidebarcontent a
  {
      padding: 2px 5px;
      color: #5377A9;
      text-decoration: none;
  }
  
  .sidebarcontent a:hover
  {
      background-color: #0F2543;
      color: #FFF;
  }
  
  .sidebarcontent a:visited
  {
      font-weight: normal;
  }
  
  #master_content
  {
      float: left;
      width: 550px;
      margin-right: -550px;
      color: #666666;
  }
  
  /*
  #master_content a
  {
      color: #5377A9;
      padding: 1px;
  }
  
  #master_content a:link
  {
  }
  
  #master_content a:visited
  {
  }
  
  #master_content a:hover
  {
      background-color: #BFBFBF;
      color:#FFF;
  }
  */
  
  #master_content ul
  {
      margin: 0 25px 0 30px;
  }
  
  #master_contentheader
  {
      height: 19px;
      background: url(images/rightcoltop.gif) no-repeat right top;
  }
  
  #master_contentplaceholder
  {
      padding: 30px 20px 40px 20px;
      border-left: 1px solid #0F2543;
      border-right: 1px solid #0F2543;
      border-bottom: 1px solid #0F2543;
      background-color: #EFEFEF;
      line-height: 1.5em;
  }
  
  #master_contentfooter
  {
      clear: both;
      padding: 10px 0 5px 10px;
      color: #333;
      font-size: 0.8em;
      letter-spacing: 0.1em;
  }
  
  /* Content Page Layout             */
  .demoarea {
      padding:20px;
      background:#FFF url(images/demotop.png) no-repeat left top;
  }
  
  .demoarea p 
  {
      padding:5px;
  }
  
  .demoheading {
      padding-bottom:20px;
      color:#5377A9;
      font-family:Arial, Sans-Serif;
      font-weight:bold;
      font-size:1.5em;
  }
  
  .demobottom {
      height:8px;
      background:#FFF url(images/demobottom.png) no-repeat left bottom;
  }
  
  
  .heading {
      padding: 1em 0 1em 0;
      color:#5377A9;
      font-family:Arial, Sans-Serif;
      font-weight:bold;
      font-size:1.2em;
  }
  
  .subheading{
      padding:.8em 0 0.5em 0;
      color:#0F2543;
      font-weight:bold;
      font-family:Arial, Sans-Serif;
      font-size:1.1em;
  }
  
  p {}
  
  em {font-style:italic}
  
  i {font-style: italic;}
  
  strong {font-weight:bold;}
  
  .codeReference
  {
      font-family: 'Courier New', Monospace;
      font-style: normal;
      font-weight: bold;
  }
  
  pre, code {
      display:block;
      margin:15px 15px 15px 0;
      padding:10px;
      border:1px dashed #CCC;
      background-color:#FFF;
      color:#000;
      font-family:'Courier New', Monospace;
      font-size:0.9em;
      font-style:normal;
  }
  
  .releaseList {
      list-style-type:disc;
  }
  
  
  /* Styles for the Animation Reference */
  .animationReferenceTable
  {
  }
  
  .animationReferenceRow
  {
  }
  
  .animationReferenceField
  {
      text-align: right;
      vertical-align: top;
      padding-top: 5px;
  }
  
  .animationReferenceCode
  {
      margin-top: 5px;
      vertical-align: top;
      font-family: 'Courier New', Monospace;
      font-style: normal;
      font-weight: bold;
  
      display:block;
      background-color:#FFF;
      color:#000;
      font-family:'Courier New', Monospace;
      font-size:0.9em;
      font-style:normal;
      font-weight: bold;
      margin-bottom: 5px;
  }
  
  .animationReferenceItems
  {
      vertical-align: top;
  }
  
  .animationReferenceItemTable
  {
      width: 100%;
      padding: 0px;
      margin: 0px;
  }
  
  .animationReferenceItemRow
  {
      width: 100%;
      padding: 0px;
      margin: 0px;
  }
  
  .animationReferenceItem
  {
      width: 100%;
      padding: 0px;
      margin: 0px;
      padding-bottom: 10px;
  }
  
  .animationReferenceItemCode
  {
      display:block;
      background-color:#FFF;
      color:#000;
      font-family:'Courier New', Monospace;
      font-size:0.9em;
      font-style:normal;
      font-weight: bold;
  }
  
  /******************************/
  /**Styling information specific to individual content pages**/
  
  /* Accordion */
  .accordionHeader
  {
      border: 1px solid #2F4F4F;
      color: white;
      background-color: #2E4d7B;
      font-family: Arial, Sans-Serif;
      font-size: 12px;
      font-weight: bold;
      padding: 5px;
      margin-top: 5px;
      cursor: pointer;
  }
  
  #master_content .accordionHeader a
  {
      color: #FFFFFF;
      background: none;
      text-decoration: none;
  }
  
  #master_content .accordionHeader a:hover
  {
      background: none;
      text-decoration: underline;
  }
  
  .accordionContent
  {
      background-color: #D3DEEF;
      border: 1px dashed #2F4F4F;
      border-top: none;
      padding: 5px;
      padding-top: 10px;
  }
  
  /*Cascading DropDown*/
  
  /*CollapsiblePanel*/
  .collapsePanel {
  
      background-color:white;
      overflow:hidden;
  }
  
  .collapsePanelHeader{   
      width:100%;     
      height:30px;
      background-image: url(images/bg-menu-main.png);
      background-repeat:repeat-x;
      color:#FFF;
      font-weight:bold;
  }
  
  #master_content .collapsePanelHeader a {color:#FFF;}
  #master_content .collapsePanelHeader a:hover {text-decoration:none;background:none;}
  
  /*Confirm Button*/
  
  /* DropShadow */
  
  #master_content .dropShadowPanel span {color:white;text-decoration:underline;}
  #master_content .dropShadowPanel span:hover {text-decoration:none;}
  
  
  .dropShadowPanel 
  {   
      width:300px;    
      background-color:#5377A9;       
      color:white;
      font-weight:bold;       
  }
  
  /*Drag Panel*/
  .dragMe {
      width:100%;
      height:21px;
      background-color:#FFF;
      background-image:url(images/header-opened.png);
      text-align:center;
      cursor:move;
      font-weight:bold;
  }
  
  .overflowHidden {overflow:hidden;}
  
  .overflowScroll {overflow:hidden;}
  
  /*Hover Menu*/
  .popupMenu {
      position:absolute;
      visibility:hidden;
      background-color:#F5F7F8;
      opacity:.9;
      filter: alpha(opacity=90);
  }
  
  .popupHover {
      background-image:url(images/header-opened.png);
      background-repeat:repeat-x;
      background-position:left top;
      background-color:#F5F7F8;
  }
  
  /* PagingBulletedList */
  .selectIndex {
      font-weight: bold;
      text-decoration:none;
  }
  .unselectIndex {
      font-weight:normal;
      text-decoration:underline;
  }
  
  
  /*Modal Popup*/
  .modalBackground {
      background-color:Gray;
      filter:alpha(opacity=70);
      opacity:0.7;
  }
  
  .modalPopup {
      background-color:#ffffdd;
      border-width:3px;
      border-style:solid;
      border-color:Gray;
      padding:3px;
      width:250px;
  }
  
  .sampleStyleA {
      background-color:#FFF;
  }
  
  .sampleStyleB {
      background-color:#FFF;
      font-family:monospace;
      font-size:10pt;
      font-weight:bold;
  }
  
  .sampleStyleC {
      background-color:#ddffdd;
      font-family:sans-serif;
      font-size:10pt;
      font-style:italic;
  }
  
  .sampleStyleD {
      background-color:Blue;
      color:White;
      font-family:Arial;
      font-size:10pt;
  }
  
  /*Popup Control*/
  .popupControl{
      background-color:White;
      position:absolute;
      visibility:hidden;
  }
  
  /*Reorder List*/
  .dragHandle {
      width:10px;
      height:15px;
      background-color:Blue;
      background-image:url(images/bg-menu-main.png);
      cursor:move;
      border:outset thin white;
  }
  
  .callbackStyle {
      border:thin blue inset;     
  }
  
  .callbackStyle table {
      background-color:#5377A9;   
      color:Black;
  }
  
  
  .reorderListDemo li {
      list-style:none;
      margin:2px;
      background-image:url(images/bg_nav.gif);
      background-repeat:repeat-x;
      color:#FFF;
  }
  
  .reorderListDemo li a {color:#FFF !important; font-weight:bold;}
  
  .reorderCue {
      border:dashed thin black;
      width:100%;
      height:25px;
  }
  
  .itemArea {
      margin-left:15px;
      font-family:Arial, Verdana, sans-serif;
      font-size:1em;
      text-align:left;
  }
  
  
  /* Rounded Corners*/
  
  .roundedPanel
  {   
      width:300px;    
      background-color:#5377A9;   
      color:white;
      font-weight:bold;       
  }
  
  /* ResizableControl */
  
  .frameImage
  {
      width:130px;
      height:65px;
      overflow:hidden;
      float:left;
      padding:3px;
  }
  
  .frameText
  {
      width:100px;
      height:100px;
      overflow:auto;
      float:left;
      background-color:#ffffff;
      border-style:solid;
      border-width:2px;
      border-color:Gray;
      font-family:Helvetica;
      line-height:normal;
  }
  
  .handleImage
  {
      width:15px;
      height:16px;
      background-image:url(images/HandleHand.png);
      overflow:hidden;
      cursor:se-resize;
  }
  
  .handleText
  {
      width:16px;
      height:16px;
      background-image:url(images/HandleGrip.png);
      overflow:hidden;
      cursor:se-resize;
  }
  
  .resizingImage
  {
      padding:0px;
      border-style:solid;
      border-width:3px;
      border-color:#B4D35D;
  }
  
  .resizingText
  {
      padding:0px;
      border-style:solid;
      border-width:2px;
      border-color:#7391BA;
  }
  
  /*Textbox Watermark*/
  
  .unwatermarked {
      height:18px;
      width:148px;
      font-weight:bold;
  }
  
  .watermarked {
      height:20px;
      width:150px;
      padding:2px 0 0 2px;
      border:1px solid #BEBEBE;
      background-color:#F0F8FF;
      color:gray;
  }   
  
  /* Rating */
  .ratingStar {
      font-size: 0pt;
      width: 13px;
      height: 12px;
      margin: 0px;
      padding: 0px;
      cursor: pointer;
      display: block;
      background-repeat: no-repeat;
  }
  
  .filledRatingStar {
      background-image: url(Images/FilledStar.png);
  
  }
  
  .emptyRatingStar {
      background-image: url(Images/EmptyStar.png);
  }
  
  .savedRatingStar {
      background-image: url(Images/SavedStar.png);
  }
  
  
  /*Toggle Button*/
  
  /*Setup*/
  .walkthrough li {padding-bottom:5px;}
  
  /*Using a sample extender*/
  
  /*Creating a new extender*/
  .walkthroughNote {
      padding-left:25px;
      font-style:italic;
  }
  
  /*Other neat stuff*/
  
  
  
  
  
  /************ PasswordStrength Related Styles ***********************/
  .TextIndicator_TextBox1
  {
       background-color:Gray;
       color:White;
       font-family:Arial;
       font-size:x-small;
       font-style:italic;  
       padding: 2px 3px 2px 3px;   
  }
  
  .BarIndicator_TextBox2
  {
      color:Blue;
      background-color:Blue;
  }
  
  .BarBorder_TextBox2
  {
      border-style:solid;
      border-width:1px;
      width:200px;
      vertical-align:middle;
  }
  
  .TextIndicator_TextBox3
  {
       background-color:Blue;
       color:Yellow;
       font-size:small;
       font-variant:small-caps;  
       padding: 2px 3px 2px 3px;   
  }
  
  .TextIndicator_TextBox3_Handle
  {
      width:16px;
      height:14px;
      background-image:url(images/Question.png);
      overflow:hidden;
      cursor:help;
  }
  
  .dynamicPopulate_Normal 
  {   
      border:silver 1px inset;
      padding:2px;
      text-align:center;
      height:2em;
      margin:5px;
      width:200px;
  }
  
  .dynamicPopulate_Updating 
  {
      background-image:url(images/loading.gif);
      background-repeat:no-repeat;
      border:silver 1px inset;
      text-align:center;
      padding:2px;
      height:2em;
      margin:5px;
      width:200px;
  }
  /************ MaskedEdit Related Styles ***********************/
  .MaskedEditFocus
  {
      background-color: #ffffcc;
      color: #000000;
  }
  .MaskedEditMessage
  {
      color: #ff0000;
      font-weight: bold;
  }
  .MaskedEditError
  {
      background-color: #ffcccc;
  }
  .MaskedEditFocusNegative
  {
      background-color: #ffffcc;
      color: #000000;
  }
  .MaskedEditBlurNegative
  {
      color: #ff0000;
  }
  
  .MyCalendar .ajax__calendar_container {
      border:1px solid #646464;
      background-color: lemonchiffon;
      color: red;
  }
  .MyCalendar .ajax__calendar_other .ajax__calendar_day,
  .MyCalendar .ajax__calendar_other .ajax__calendar_year {
      color: black;
  }
  .MyCalendar .ajax__calendar_hover .ajax__calendar_day,
  .MyCalendar .ajax__calendar_hover .ajax__calendar_month,
  .MyCalendar .ajax__calendar_hover .ajax__calendar_year {
      color: black;
  }
  .MyCalendar .ajax__calendar_active .ajax__calendar_day,
  .MyCalendar .ajax__calendar_active .ajax__calendar_month,
  .MyCalendar .ajax__calendar_active .ajax__calendar_year {
      color: black;
      font-weight:bold;
  }
  
  .validatorCalloutHighlight 
  {
      background-color: lemonchiffon; 
  }
  </code></pre>
  
  <p>I am getting the following errors:</p>
  
  <blockquote>
    <p>Error 1   Validation (CSS 2.1): 'opacity' is not a known CSS property
    name. C:\Documents and Settings\agordon\My Documents\Visual Studio
    2008\WebSites\WebSite3\StyleSheet.css 402 2   C:...\WebSite3\
    Error 2   Validation (CSS 2.1): 'filter' is not a known CSS property
    name. C:\Documents and Settings\agordon\My Documents\Visual Studio
    2008\WebSites\WebSite3\StyleSheet.css 403 2   C:...\WebSite3\
    Error 3   Validation (CSS 2.1): 'filter' is not a known CSS property
    name. C:\Documents and Settings\agordon\My Documents\Visual Studio
    2008\WebSites\WebSite3\StyleSheet.css 427 2   C:...\WebSite3\
    Error 4   Validation (CSS 2.1): 'opacity' is not a known CSS property
    name. C:\Documents and Settings\agordon\My Documents\Visual Studio
    2008\WebSites\WebSite3\StyleSheet.css 428 2   C:...\WebSite3\
    Error 5   Validation (CSS 2.1): 'lemonchiffon' is not a valid value for
    the 'background-color' property.  C:\Documents and Settings\agordon\My
    Documents\Visual Studio
    2008\WebSites\WebSite3\StyleSheet.css 738 23  C:...\WebSite3\
    Error 6   Validation (CSS 2.1): 'lemonchiffon' is not a valid value for
    the 'background-color' property.  C:\Documents and Settings\agordon\My
    Documents\Visual Studio
    2008\WebSites\WebSite3\StyleSheet.css 759 23  C:...\WebSite3\</p>
  </blockquote>
  
  <p>Does anyone know what I am doing wrong?</p>