I'm using the following calcualtion to determine the pay for an instructor based on the number of days a student was enrolled in a course before he/she dropped. This works, but what i can't figure it out is how to make it ONLY look for those students who have a date in Date Dropped. the way I have it setup now it looks through all students.

If (Date Dropped - Date Enrolled >= 60, 50, 25)

I'd love some help.

Essentially, I want this field to return a null value if the Date Dropped field is empty.

Try wrapping your calc inside a not IsEmpty ( Date Dropped ) condition, e.g.

Case (

not IsEmpty ( Date Dropped ) ;

Choose ( Date Dropped - Date Enrolled < 60 ; 50 ; 25 )

)

That almost looks like the answer I gave on another thread.

Thanks for everyone's help. here's what I've got from your suggestions. And I should preface this by saying that I am using FileMaker 4.

Solution #1 suggestion:

Case (

not IsEmpty ( Date Dropped ) ;

Choose ( Date Dropped - Date Enrolled < 60 ; 50 ; 25))

Error message:

Either an operator was omitted, this function, cannot be found, or "(" was not expected here. (it highlights "Choose")

Solution #1 suggestion:

If( not IsEmpty(DateDropped);

If( DateDropped - DateEnrolled >= 60; 50; 25 ))

Error message:

This field cannot be found. (it highlights DateDropped...this is exaclty how the field name is spelled)

Help!!! :

Try replacing the semi-colons with commas.