Fill check box when another field is not empty

[sleake]

I've created an unbound check box for display on a form that I want to fill (-1) when an Attachment field is not empty. (Just want to know whether there is an attachment.)



I tried creating an expression as the control source of the check box, but received an error about incorrect syntax.

Here's the expression I tried: Iif (Not IsEmpty(AttachmentField, -1, 0)).

Would appreciate your help.

[RuralGuy]

I would try putting code in the On Current Event.

[Micron]

One half of the IIF expression is what to do if true, the other part is for what to do if it's not, so you don't use the logical operator "Not". you could use an event (AfterUpdate or LostFocus, or maybe even Change) on the textbox to set the checkbox to be True or False when that event fires. Or you could try =IIf(IsNull([AttachmentField]),0,-1).
IsEmpty is supposed to be used for a varaiant data type, which I doubt your textbox is.

[Missinglinq]

While the argument is a Variant containing a numeric or string expression...IsEmpty() actually indicates whether or not a Variable has been initialized.

Linq ;0)>