JAVASCRIPT SCRIPT FOR VALIDATE TEXTBOX

Script
-------------
function getKeyCode(e)
{
if (window.event)
return window.event.keyCode;
else if (e)
return e.which;
else
return null;
}
function keyRestrict(e, validchars)
{
var key='', keychar='';
key = getKeyCode(e);
if (key == null) return true;
keychar = String.fromCharCode(key);
keychar = keychar.toLowerCase();
validchars = validchars.toLowerCase();
if (validchars.indexOf(keychar) != -1)
return true;
if ( key == null key == 0 key == 8 key == 9 key == 13 key == 27 )
return true;
return false;
}
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Calling the function
SERVER SIDE;
OR PUT

txtSRange.Attributes.Add("onkeypress", "return keyRestrict(this,'1234567890');");