Force a refresh of displayed values on the screen. This function is useful if you want to use buttons to change values as in:
:SCREEN ONLY
SHOWVAR,"FINAL_TIME",10,10,0,0,L
BUTTON,"Small",10,20,0,0,L,,SIMULATE>SETVAL|FINAL_TIME=80&SPECIAL>REFRESH
BUTTON,"Big",10,30,0,0,L,,SIMULATE>SETVAL|FINAL_TIME=800&SPECIAL>REFRESH
