Image in Textbox

.tb11 {   
    background:#FFFFFF url(search.png) no-repeat 4px 4px;    
    padding:4px 4px 4px 22px;    
    border:1px solid #CCCCCC;    
    width:230px;    
    height:18px;    
}<div class="tb5">   
      <asp:TextBox ID="TextBox1" runat="server" CssClass="tb5a"></asp:TextBox>    
  </div>