var PSSN = ParticipantSSN.rawValue; // Length is 9var mask = "XXX-XX-";if(chkPredact.rawValue == false) {fltParticipantSSN.rawValue = PSSN;}else{fltParticipantSSN.rawValue = mask + PSSN.substring(5,9);}

On my form, I want to give the user the option to mask SSN. If checkbox = true, then only display last 4 digits of the SSN.  Then in the document, it will display value via a floating field.  I cannot figure out how to concatenate the mask and only display the last 4 digits of the SSN string.  The D...