One for Access Users

[Hecate]

I am running a query which pulls the start date and end date from unbound controls on a form. I have a command button which opens the date input form but I need it to wait until I have entered the dates before running the query. I use the same date input form for different queries so I can't use the after update property of the date field. The best I have come up with so far is a continue button on the date form but this means a different button for each query. I would like to put something in the query's SQL which waits until the date form end date is not null but I haven't managed to come up with anything so far. Any suggestions would be welcome.

 

I am using Access 2003 if that makes a difference