subroutine OS_OpenDialog (string : Primary_Window_Name,
string : Title_For_Open_Dialog,
string : File_Name,
integer : Error_Level)
subroutine OS_SaveAsDialog (string : Primary_Window_Name,
string : Title_For_SaveAs_Dialog,
string : File_Name,
integer : Error_Level)
Display the standard file Open and Save As dialogs.
Primary_Window_Name must contain the name of the program's primary region.
Title string contains the text to appear in the dialog's title bar.
File_Name is populated with the path and name of the selected file.
Error_Levels are:
0 Normal completion; File_Name is valid.
1 User cancelled the dialog.
-1 Primary Window Name is invalid.
NB: these routines do NOT open or save the file; they simply return the file name.