Clear field, clear variable too.

[#1]

Hi,

I have a trigger on a variable, so when I enter the variable it will trigger a selection in a field, when I clear this field, is there anyway I can also clear a variable?

Example:

var_Date ='01/01/14'

Trigger: On input var_Date, make selection in field: OrderDate.

I then hit Clear, on Field: OrderDate.

How do I make this also clear the var_Date?

James.