Purpose With SelectDirectory you can open a dialog box that lets the user specify the name of a directory
Example SelectDirectory name="MM_dir"
Format SelectDirectory name="dirname"

The standard dialog box for directory selection is called up. When the call returns, the variable  V[dirname] contains the selected directory name.
if Q[ok]  you can query whether the user has selected a directory.

title= Title of the dialog box
directory= The initial directory
Components GuiXT + InputAssistant