Creating alert or confirmation box in ASP .Net

Hi,

Its very easy, assumed that you have a textbox and a button and you want to alert the user on the button click if its text is empty,

<table>
       <tr>
           <td>
               <asp:textbox id="txtTest" runat="server" xmlns:asp="#unknown"></asp:textbox>
           </td>
           <td>
               <asp:button id="btnTest" runat="server" text="Click Me!!!" onclientclick="return ShowAlert();" xmlns:asp="#unknown" />
           </td>
       </tr>
   </table>

now here is the javascript function to get the alert when the textbox is empty.

<script type="text/javascript">
       function ShowAlert() {
           var txt = document.getElementById('txtTest').Value;
           if (txt == '') {
               alert('textbox is empty');
               //or if you want to get a confirm alert Box then
               if (confirm('Do you want ot proceed?')) {
                   alert('proceeding................');
               }
               else {
                   alert('canceled.................');
               }
           }
       }
   </script>