For records in the data set being queried which meet whichever of the two criteria has been selected by the action of the IIF statement, a value of -1 is returned. Assuch the correct syntax is actually IIF. In a form, you want to denote whether Italian is the first language of the contact.
For more information about working with VBA, select Developer Reference in the drop-down list next to Search and enter one or more terms in the search box. Since each nested IIf function is the falsepart argument of the IIf function that contains it, the text "Some other language" is only returned if all the expr arguments of all the IIf functions evaluate to False.
The IIF statement has to be setup as a Field in the query. For example, if evaluating falsepart results in a division by zero error, an error occurs even if expr is True. Where a Job No is provided on the dialog box, valid or otherwise, the result of the IIF statement becomes False which sets the criteria to select only matching job numbers.
Only records with the same number as the selected Job No will be selected. This is where calculations and formulae are normally placed, however, in this case no field name has to be given.