>I tried IIF(myvar,"Title1","Title2") in the form caption.
>I also tried &IIF(myvar,"Title1","Title2")
>It was as is in the window, it wasn't changed to "Title1" or "Title2".
>
>What did I missed ?

The caption holds a character string - it's evaluated once and once only per assignment. If you want to update it, you need to reassign its value - a timer in the form that fires and re-evaluates the caption periodically will handle this.