title: add a property to asp.net user control and display as attribute on output html
body: <p>my (TextBox user control) Date property:</p>
  
  <pre><code>    [Category("Behavior"),
      Description("convert the current text to DateTime")]
      public DateTime? MyDate
      {
          get
          {                
              return ChangeDate();
          }
          set
          {
              Text = ToDateString(value);
          }
      }
  </code></pre>
  
  <p>and in asp.net:</p>
  
  <pre><code>&lt;my:XTextBox ID="XTextBox1" runat="server"&gt;&lt;/my:XTextBox&gt;
  </code></pre>
  
  <p>i want to see this property like <strong>Text</strong> Property on output:</p>
  
  <pre><code>&lt;input name="XTextBox1" type="text" id="XTextBox1" MyDate="2013-10-11" /&gt;
                                                     ^^^^^^^^^^^^^^^^^^^
  </code></pre>
  
  <p>so in code behind i can access to <strong>MyDate</strong> like this?!</p>
  
  <pre><code>protected void Page_Load(object sender, EventArgs e)
  {
      Label1.Text = XTextBox1.MyDate;
  }
  </code></pre>
  
  <p>thanks in advance..</p>