Side effect of DoPrompt statement on display

The following code displays a wave, then it asks the user for some interaction. In my igor, the textbox is not visible when the input dialog comes up, only after it has finished. Is this behaviour intended? Can it be changed? (I would like to read the text in the textbox before continuing. If the Display statement were in a loop, the textbox would never become visible.)

Function d(w)
Wave w
Variable bla
Display w
TextBox "text"
Prompt bla, "Do not enter anything here:"
DoPrompt "Press continue", bla
End