Fill in the scripting gaps please....?!?!

Hi all,

Trying to make use of scripting successfully for the first time and can't help but think there's still a fair amount to do to the code below...

Simply trying to populate a custom field (custom_217) upon saving the form with the sum of two other fields (custom_49  &  custom_39).

Any help would be brilliant!!

Cheers,

Tom




function predval () {
   
   var predictedvalue = new NSOA.record.oaProject('custom_217');

var estval = NSOA.form.getValue('custom_49__c');
var probfac = NSOA.form.getValue('custom_39__c');

var ResultField = estval * probfac;
   
predictedvalue = ResultField;
   
var results = NSOA.wsapi.modify([],[predictedvalue]);
}