R_IsVGAFl()
 Determine if an VGA card is present
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 Syntax
        lIsVGA := R_IsVGAFl ()

 Parameters
        None

 Returns
        lIsVGA          .T. :   VGA card is present or can be emulated
                        .F. :   No VGA card present

 Description
        This function can determine if the PC supports VGA.

 Example
        IF R_IsVGAFl ()
                *-- VGA present
                R_VGAFnt ( 2 )          && Load internal VGA font
        ELSE
                IF R_IsEGAFl ()
                        R_EGAFnt ( 2 )  && Load internal EGA font
                ELSE
                        Alert ( 'PC must at least support EGA !' )
                ENDIF
        ENDIF