JavaScript lastIndexOf() Method

  1. <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="index2.aspx.cs" Inherits="MyApp.index2" %>  
  2.   
  3. <!DOCTYPE html>  
  4. <html xmlns="http://www.w3.org/1999/xhtml">  
  5. <head runat="server">  
  6.     <title></title>  
  7.     <script type="text/javascript">  
  8.         function getTopLevelDomain() {  
  9.             var url = document.getElementById("txtURL").value;  
  10.             if (url == "") {  
  11.                 alert("Please enter a valid URL");  
  12.                 document.getElementById("txtURL").focus();  
  13.             }  
  14.             else {  
  15.                 var domain = url.substring(url.lastIndexOf("."));  
  16.                 document.getElementById("txtDomain").value = domain;  
  17.             }  
  18.         }  
  19.     </script>  
  20. </head>  
  21. <body>  
  22.     <form id="form1" runat="server">  
  23.         <div>  
  24.             <table style="border: 1px solid blue; font-family: 'Comic Sans MS'">  
  25.                 <tr>  
  26.                     <td>  
  27.                         <h3>Top level Domain Checker</h3>  
  28.                     </td>  
  29.                 </tr>  
  30.                 <tr>  
  31.                     <td>Enter the URL :  
  32.                     </td>  
  33.                     <td>  
  34.                         <input id="txtURL" type="text" />  
  35.                     </td>  
  36.                     <td>  
  37.                         <input id="btnFetch" type="button" value="Fetch" onclick="getTopLevelDomain();"  
  38.                             style="font-family: 'Comic Sans MS'" /></td>  
  39.                 </tr>  
  40.                 <tr>  
  41.                     <td>Top Level Domain : </td>  
  42.                     <td>  
  43.                         <input id="txtDomain" type="text" disabled="disabled" />  
  44.                     </td>  
  45.                 </tr>  
  46.             </table>  
  47.         </div>  
  48.     </form>  
  49. </body>  
  50. </html>