To make telephone number field box only accept number

catalog/view/javascript/common.js
add this function in the bottom file

function isNumberKey(evt) {
   var charCode = (evt.which) ? evt.which : event.keyCode
   if (charCode > 31 && (charCode < 48 || charCode > 57)) {
      return false;
   } else {
      return true;
   }
}

 

catalog/view/theme/default/template/account/register.tpl

<input type="text" name="telephone" onkeypress="return isNumberKey(event)" value="<?php echo $telephone; ?>" size="32"/>

Thanks to : avvici -arvixe-