INSTR is an input string that appears in the dialog box as instructions to the
user. PATH is an output string that gives the full path of the folder selected
by the user. If a valid folder is not selected or the user clicks on the CANCEL
button, PATH is returned as an empty string and the function returns .FALSE..
You can provide an initial PATH, that is automatically selected when the
dialog is opened, by making a prior call to the subroutine