DIALOG_MESSAGE - Creates modal message dialog.
DIALOG_PICKFILE - Creates native file-selection dialog.
DIALOG_PRINTERSETUP - Opens native dialog used to set properties for a printer.
DIALOG_PRINTJOB - Opens native dialog used to set parameters for a print job.
DIALOG_READ_IMAGE - Presents GUI for reading image files.
DIALOG_WRITE_IMAGE - Presents GUI for writing image files.