twWSaveMem()
 ----------------------------------------------------------------------------
     Save the current window to a .MEM file. The names of the files
     will be 'SCRNxxx.SCR' where xxx is a number incremented as windows
     are saved DURING THE CURRENT SESSION. There is not, at present,
     the option to define the filename to which the windows are to be
     saved.

     It is suggested that this function is useful in developing
     libraries of windows to be predefined and restored when an
     application runs, with the RESTORE FROM then RESTSCREEN commands.
     The function can be defined with a SET KEY, called when needed and
     commented out when it is time to deliver the application.

       Arguments:

     None.

       Return:

     Current window handle.

       Example:

     SET KEY 287 TO twWsaveMem

     Sets the ALT-S key to save windows to .MEM files.