validation on phone no

Hi,

You could do it with a small JavaScript. Add the onclick attribute to the button in the Page_Load method, like this:

btnSubmit.Attributes.Add("onclick", "return checkTxtBox();");

Then add the following script to the page or a .js file imported to the page:

(Make sure to change the textbox names to your names)
<script type="text/javascript">
function checkTxtBox()
{
  var t1 = document.getElementById('txtNo1').value; // You could also use <% = txtNo1.ClientID %>
  var t2 = document.getElementById('txtNo2').value;
  var t3 = document.getElementById('txtNo3').value;
  if (t1 != '' || t2 != '' || t3 != '')
  {
  return true;
  }
  else
  {
  alert('You need to fill in at least on phonenumber...');
  return false;
  }
}
script>