AMOSi:Cls
an example can be found on AMOSPro_Examples:Examples/H-3/Help_39.AMOS
CLears all or part of a Screen in one of three ways:
Cls
Clears entire screen using the current paper colour.
Cls colour
Clears screen using the selected colour index.
Cls colour,tx,ty To bx,yb
Erases the block from tx,ty to bx,by