This blog give the information like how generate popup window on button click  using the jquery.
 
 Look 
 
 For that create the new project and take a one webform:
 
 ![new web form]()
 
 After that go to:
 
 Select project--->Right Click->Add New Item->and Select Webform
 
 ![add new web form]()
 
 Output
 
 ![sample web page]()
 
 And after click on button:
 
 ![popup button]()
 
 If you do not select any radio button and click onsubmit button the it gives  alert message
 
 ![radio button validate]()
 
 Sample.aspx
 
 Design
 
- <html>  
 - <body>  
 -     <form id="form1" runat="server">  
 -     <asp:Button Text="Modal Dialog" runat="server" ID="btnShowModal" />  
 -     <asp:Button Text="Sample Dialog" runat="server"  ID="btnShowSimple" Visible="false"/>  
 -     <br />  
 -     <br />  
 -     <div id="output"></div>  
 -     <div id="overlay" class="web_dialog_overlay"></div>  
 -     <div id="dialog" class="web_dialog">  
 -         <table style="width: 100%; border: 0px;" cellpadding="3" cellspacing="0">  
 -             <tr>  
 -                 <td class="web_dialog_title">Online Survey</td>  
 -                 <td class="web_dialog_title align_right"><a href="#" id="btnClose">Close</a></td>  
 -             </tr>  
 -             <tr>  
 -                 <td> </td>  
 -                 <td> </td>  
 -             </tr>  
 -             <tr>  
 -                 <td colspan="2" style="padding-left: 15px;"><b>In Wchich Country You Belongs? </b></td>  
 -             </tr>  
 -               
 -             <tr>  
 -                 <td colspan="2" style="padding-left: 15px;">  
 -                    <asp:RadioButtonList runat="server" ID="brands">  
 -                         <asp:ListItem Text="India" Value="India" />  
 -                         <asp:ListItem Text="America" Value="America" />  
 -                         <asp:ListItem Text="Canada" Value="Canada" />  
 -                         <asp:ListItem Text="Chaina" Value="Chaina" />  
 -                     </asp:RadioButtonList>  
 -                 </td>  
 -             </tr>  
 -               
 -             <tr>  
 -                 <td  style="text-align: center;"><asp:Button Text="Submit" runat="server" ID="btnSubmit" /></td>  
 -                 <td  style="text-align: center;"><asp:Button Text="Cancel" runat="server" ID="btnClose" /></td>  
 -             </tr>  
 -         </table>  
 -     </div>  
 -    </form>  
 - </body>  
 - </html>  
 
  Script
 - <script type="text/javascript">  
 -   
 -         $(document).ready(function () {  
 -              
 -             $("#brands").attr("checked", false);  
 -             $("#btnShowModal").click(function (e) {  
 -                 ShowDialog(true);  
 -                 e.preventDefault();  
 -             });  
 -   
 -             $("#btnClose").click(function (e) {  
 -                 HideDialog();  
 -                 e.preventDefault();  
 -             });  
 -   
 -             $("#btnSubmit").click(function (e) {  
 -                 if ($("#brands").find("input:checked").length > 0) {  
 -                     var brand = $("#brands input:radio:checked").val();  
 -                     $("#output").html("<b>Your Country Is : </b>" + brand);  
 -                     alert(" Your Country Is " + brand);  
 -                     HideDialog();  
 -                     e.preventDefault();  
 -                 }  
 -                 else {  
 -                     alert("Please select Radio Button")  
 -                     ShowDialog(true);  
 -                     e.preventDefault();  
 -                 }  
 -             });  
 -   
 -         });  
 -   
 -         function ShowDialog(modal) {  
 -             $("#overlay").show();  
 -             $("#dialog").fadeIn(300);  
 -   
 -             if (modal) {  
 -                 $("#overlay").unbind("click");  
 -             }  
 -             else {  
 -                 $("#overlay").click(function (e) {  
 -                     HideDialog();  
 -                 });  
 -             }  
 -         }  
 -   
 -         function HideDialog() {  
 -             $("#overlay").hide();  
 -             $("#dialog").fadeOut(300);  
 -         }   
 -           
 -     </script>  
 
  CSS Code - <style type="text/css">  
 -         .web_dialog_overlay  
 -         {  
 -             position: fixed;  
 -             top: 0;  
 -             right: 0;  
 -             bottom: 0;  
 -             left: 0;  
 -             height: 100%;  
 -             width: 100%;  
 -             margin: 0;  
 -             padding: 0;  
 -             background: #000000;  
 -             opacity: .15;  
 -             filter: alpha(opacity=15);  
 -             -moz-opacity: .15;  
 -             z-index: 101;  
 -             display: none;  
 -         }  
 -         .web_dialog  
 -         {  
 -             display: none;  
 -             position: fixed;  
 -             width: 300px;  
 -             height: 215px;  
 -             top: 50%;  
 -             left: 50%;  
 -             margin-left: -190px;  
 -             margin-top: -100px;  
 -             background-color: #ffffff;  
 -             border: 2px solid #336699;  
 -             padding: 0px;  
 -             z-index: 102;  
 -             font-family: Verdana;  
 -             font-size: 10pt;  
 -         }  
 -         .web_dialog_title  
 -         {  
 -             border-bottom: solid 2px #336699;  
 -             background-color: #336699;  
 -             padding: 4px;  
 -             color: White;  
 -             font-weight: bold;  
 -         }  
 -         .web_dialog_title a  
 -         {  
 -             color: White;  
 -             text-decoration: none;  
 -         }  
 -         .align_right  
 -         {  
 -             text-align: right;  
 -         }  
 -     </style>