TextBox.BeforeUpdate Property (Access)
Returns or sets which macro, event procedure, or user-defined function runs when the BeforeUpdate event occurs. Read/write String.
expression A variable that represents a TextBox object.
Valid values for this property are " macroname" where macroname is the name of macro, "[Event Procedure]" which indicates the event procedure associated with the BeforeUpdate event for the specified object, or " = functionname () " where functionname is the name of a user-defined function.
The following example specifies that when the BeforeUpdate event occurs on the first form of the current project, the associated event procedure should run.
Forms(0).BeforeUpdate = "[Event Procedure]"