FULL SCREEN how to do it-ask for help

To open OpenGL window I use:

i=winio@('%es%sv%sp%ww[no_caption,no_sysmenu,no_border]%pv%^og[DOUBLE]%lw',xo1,yo1,xo2,yo2,opengl_proc,ctrl)

Optionaly to open an OpenGL window in FULLSCREEN mode I use:

i=winio@('%es%sv%sp%ww[no_caption,no_sysmenu,no_frame,no_border]%pv%^og[DOUBLE]%lw',0,0,xres,yres,opengl_proc,ctrl)

Is it possible to switch between this two modes while a program is runing. In classic an OpenGL programing and opening window it can be doing by:

case 'f': call glutFullScreen() case 'w': call glutReshapeWindow(500, 500) call glutPositionWindow(50, 50)

but i FTN95 glut command call glutFullScreen() doesn't work - why ?

Thanks for help.