DispChar()

         Writes a character on the screen

    Syntax:

         DispChar ( nChar, nX, nY, nFore, nBack ) -> Nil

         nChar : ASCII value of the character to be printed
         nX    : Coordinate X
         nY    : Coordinate Y
         nFore : The colour of the character
         nBack : The colour of the background

    Description:

         It writes a character in graphic mode. The mode must be EGA or VGA.

    Return:

         Nothing.

    Example:

         DispChar ( Asc ( "A" ), 20, 30, 2, 0 )