GT_ALERT()       Alert() replacement
 GT_AMSG()        Boxed multi line message
 GT_ASKUSER()     Ask the user a question
 GT_BARBOX()      Display a box containing a bar area
 GT_BARCLEAR()    Clear the bar area on the screen
 GT_BARUPDATE()   Update a bar on screen
 GT_BLATBOX()     Draw a double lined box with a shadow around a text string
 GT_BLOCK()       Draws a '3d(ish)' box, and opptionally labels it
 GT_COLORSET()    Change/return the colour setting
 GT_COLORTON()    Converts Clipper colour string to numeric attribute
 GT_COLORWIN()    Colours an area of the screen.
 GT_CSHADOW()     'C' Shadow routine that works with DISPBEGIN()/DISPEND()
 GT_ELEVBAR()     Output an elevator bar on screen
 GT_ERROR()       Display an error message on the screen and wait for response
 GT_HILITE()      Change the flash brightnes etc of a colour string.
 GT_INTERRUPT()   GET/SET block for screen saver interrupts
 GT_MESSAGE()     Display a message in a box on the screen
 GT_NEWSCREEN()   Completely redraw the screen with a header.
 GT_NTOCOLOR()    Converts numeric attribute to Clipper colour string
 GT_PRINTSCREEN() Output a screen to the printer
 GT_RESTSCR()     Restore a screen.
 GT_SAVESCR()     Save a screen.
 GT_SHADOW()      Function to display a shadow around a box
 GT_THEWALL()     Draws a wall on screen. For Floyd fans only! <g>
 GT_VIDEOMODE()   Set the video mode
 GT_WARNING()     Output a warning message in white on red
 GT_WINDOW()      Display a boxed window on the screen.
 GT_WORKING()     Output "Working" in white on red on the bottom line