What field called the field event

Hello all,

I have a field event that gets called from 2 different fields (on change). In the Server section of the event I need to know which field made the call to this event (which field the user changed). I know I can pass the field value to the server like so:

Client:
params["value"]=this.getValue();

Server:
if (parameters["values"] == "something") {...

Is there a way to get the field name instead of the value?

Thanks,
Tim