OnlyNum (Javascript)
[Java Script ]

function onlynum(e)
   {
   if (e.which)
      {
      if(e.which!=44 && e.which!=8 && (e.which<48 || e.which>57))
      return false;
      }
   else if(e.keyCode)
      {
      if(e.keyCode!=44 && e.keyCode!=8 && (e.keyCode<48 || e.keyCode>57))
      return false;
      }
   return true;
   }