Home/ Questions/Q 7488471
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-29T14:55:13+00:00

The code below kinda works except yes.com is shown as valid while I need

  • 0

The code below kinda works except yes.com is shown as valid while I need to accept only this format ns1.yes.com, www.yes.com, accepting numbers and no dash or dot at the front or at the end of nameserver. Help me please.

 <html>
 <head>
<title>Validate name server</title>
<script type="text/javascript">

    function validSubdomain() {
        var re = /^[a-zA-Z0-9][a-zA-Z0-9.-]+[a-zA-Z0-9]$/;
        var val = document.getElementById("nameserver").value;

    if(val == ''){
         alert("Please enter the name server"); 
         return false; 
    } 
        if(re.test(val)) { 
            alert("valid format");
        }

        if(!re.test(val)) {
            alert("invalid format");
        }

    }
    </script>        
     </head>

     <body>
     Insert nameserver :  <input name="txt_domain" id="nameserver" type="text" size="30" /> <input name="btn_validate" type="button" value="Validate" onclick="validSubdomain()" />
     </body>
    </html>

Demo page: http://khamis.cheapantivirus.me/

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Split the value by dots and count the resulting parts.

    var parts = val.split('.');
if (parts.length < 3) { alert('invalid') }
    • 0