What is "s3"? Where did you define it? Is that supposed to be the check-box value?
And what should happen if the box is not ticked?
Ignore the If s3 statement as I was trying something but it did not work.
OK. So what code did you use, then?
Right now, this is what is in there:
// Get the field values, as strings
var s1 = getField("First Name").valueAsString;
var s2 = getField("Last Name").valueAsString;
// Combine values, separated by a period
event.value = s1 + "." + s2 + "@domain.com";
Also is there a way to truncate one of the fields to like the 1 character?