How to do it...

1. Navigate to Settings | Solutions | Packt.
2. Click on Web Resources and double-click on packt_common.js.
3. Click on Text Edit and change the populateWithTodaysDate code to the following:

packtNs.common.populateWithTodaysDate =  function(attributeToMonitor, dateAttributeToChange) 
{ 
  if (Xrm.Page.getAttribute(attributeToMonitor).getValue() !== null && 
     Xrm.Page.getAttribute(dateAttributeToChange).getValue() === null) 
  { 
    Xrm.Page.getAttribute(dateAttributeToChange).setValue(
       new Date()); 
  } 
} 

1. Add the following function:

packtNs.common.wireOnChangeEvents = 
   function(eventAttributeTuples){ 
for (var i in eventAttributeTuples) { 
  Xrm.Page.getAttribute(eventAttributeTuples[i].attribute)
     .addOnChange(eventAttributeTuples[i].function); 
  } 
} 

1. Replace the loadEvent function with the following code:

packtNs.graduateForm.loadEvent = function(){
  packtNs.common.wireOnChangeEvents([
    {attribute: "packt_supervisor",
      function: 
        packtNs.common.populateWithTodaysDate("packt_supervisor",
        "packt_postgraduatestartdate")
     }
  ]);
}

1. Click on OK, followed by PUBLISH, and then close the dialog.