You can use below eScript on Pre Set Field Value (recommended) or Set Field Value on Business Component Server Script. if (FieldName = "SSN") { var SSNNum = this.GetFieldValue("SSN"); var sErrTxt = TheApplication().LookupMessage("User Defined Errors","Wrong SSN"); var result = isNaN(SSNNum); // is not a number var length = SSNNum.length; // Length Count if (result) { TheApplication().RaiseErrorText(sErrTxt); } else if (length < "15" || length > "15") { TheApplication().RaiseErrorText(sErrTxt); } }