var phone_field_length=0;
function TabNext(obj,event,len,nextid) {	
	if (event == "down") {
		phone_field_length=obj.value.length;
		}
	else if (event == "up") {
		if (obj.value.length != phone_field_length) {
			phone_field_length=obj.value.length;
			if (phone_field_length == len) {
				var next_field = document.getElementById(nextid);
				if (next_field==null) return;
				next_field.focus();
				}
			}
		}
	}