Small Basic: Program that interupt

This the example of sub that interrupt the main loop i.e. main program:
'maincode
GraphicsWindow.MouseDown = mousclick 

For i = 0 to 10000000000
  TextWindow.WriteLine("Hello")
  Program.delay(1000)
endfor

sub mousclick
if Mouse.IsLeftButtonDown = "true" then
Program.End()
endif
endsub