Phone number validation in crm 2011

The Below snippet is essential for Validating Phone no in CRM2011. Add the JavaScript as Web Resource in CRM. Add Web Resource as On-Change Event of a particular Phone no field. Also check the option of Pass Execution Context as first parameter in handler properties.

function validatePhone(context)
{

var phone =context.getEventSource().getValue();
var sTmp = phone.replace(/[^0-9]/g, "");
phoneRegex = /^\d{10}$/;

if( !sTmp.match( phoneRegex ) )
   {
   event.returnValue = false;
   alert("Phone must contain 10 numbers.") ;
   }
else
  {
   var sTmpClean =  "(" + sTmp.substr(0, 3) + ") " + sTmp.substr(3, 3) + "-" + sTmp.substr(6, 4);
   context.getEventSource().setValue(sTmpClean);
  }
}


 Here the Phone no is validated that it contains 10 Characters and all are numeric and later placed in a Pr-defined format which is "(xxx)xxx-xxxx".