title: body Margin property not working
body: <p>Here is my code In HTML</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
      &lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;
      &lt;title&gt;Selection&lt;/title&gt;
      &lt;link rel="stylesheet" href="style.css"&gt;
        &lt;/head&gt;
        &lt;body &gt;
     &lt;div id="container"  &gt;
    &lt;form action="http://localhost:8084/CBGS/Allocate" method="Get"&gt;        
      &lt;h1&gt;College EXAM SECTION&lt;/h1&gt;
  &lt;div id="sem"&gt;Semester:
  &lt;select name="sem"&gt;
  &lt;option value="3" &gt;Sem3&lt;/option&gt;
  &lt;option value="4"&gt;Sem4&lt;/option&gt;
    &lt;option value="5"&gt;Sem5&lt;/option&gt;
   &lt;option value="6"&gt;Sem6&lt;/option&gt;
   &lt;/select&gt;
   &lt;/div&gt;   
     &lt;div id="branch"&gt;Branch:         
              &lt;select name="branch"&gt;
    &lt;option value="IT" &gt;IT&lt;/option&gt;
    &lt;option value="COMP"&gt;COMP&lt;/option&gt;
  &lt;option value="MECH"&gt;MECH&lt;/option&gt;
  &lt;option value="CIVIL"&gt;CIVIL&lt;/option&gt;
  &lt;option value="EXTC"&gt;EXTC&lt;/option&gt;
   &lt;/select&gt;
     &lt;/div&gt;
           &lt;div id="exam"&gt;   
               &lt;input type="radio" name="exam" value="R" /&gt;REGULAR&lt;br&gt;
    &lt;input type="radio" name="exam" value="K"/&gt;KT                
           &lt;/div&gt;
   &lt;div id="numberstudent"&gt;
      No of student
   &lt;input type="number" name="noOfStudent" min="1" max="100"&gt;
    &lt;/div&gt;
    &lt; input type ="submit"&gt;
  
  &lt;/form&gt;
  &lt;/div&gt;         
  &lt;/body&gt;
  
   &lt;/html&gt;
  </code></pre>
  
  <p>and style .css is</p>
  
  <pre><code>  body
  {
   margin: 0px auto;
  width:700px;
  
      //margin:0 auto;
  //margin-left:50px;
  font-family:Arial, Helvetica, sans-serif;
  font-size:100%; 
      color: white;
  line-height:1em;
  background-image: url("image/tail-middle.jpg");
      background-repeat: repeat-y;
  
   }
  
  
  #container
  {
  
  background:url(image/newsletter-bg.gif) ;
  display: block;
  
   border-radius:10px;
    // border:10px solid ;//#EE872A;
  //background-color: yellow;
  width:600px;
  margin-left: auto;
  margin-right: auto;
  margin-top: 10%;
  padding: 20px;
  
       }
     h1{
  //color: black;
  margin-left: 20px;
  }
  
  #sem , #branch, #exam,#numberstudent {
  display: block;
  //color: blueviolet;
  
  
  }
   #branch,#sem {
   float: left;
  
  }
  
  #exam{
   clear: both;
   }
  
   #numberstudent{
   margin-left: auto;
   margin-right: auto;
    }    
  </code></pre>
  
  <p>but here margin:0 auto not work,as my image not shift towards center,even i use margin-left it also not working,what wong in my code,any suggestion are most welcome</p>