How can i put formulation between two colums

[ahakeem84]

Dear Sir:

Please send me a smple rule that i can put formulation like (this-
this=this).

Thanks

 

[fredg]

Dear Sir:

Please send me a smple rule that i can put formulation like (this-
this=this).

Thanks

As control source in an unbound control, write:
=[Field1] - [Field2]