Draw animimage to desktopbuffer

I am writting a simple screenlet for my GF because she is obsessed with frogs. Anyway, is there an alternative to cls because that causes the whole thing to black out. Otherwise, it leaves frog trails. I've been programming with Blitz for years, but I haven't used it lately, so you needn't dummy it down for me. Thanks!

Here's something I whipped, so it's a little rough. Basically all you do is grab the current desktop buffer and use DrawBlock instead of Cls to reset the background. The only problem I've found is it doesn't seem to catch any events so I'm not sure how you'd quit such an app. Anyway, hope this helps :)

Local background	= CreateImage(GadgetWidth(Desktop()), GadgetHeight(Desktop()))
Local myTimer		= CreateTimer(60)

; Grab the background
CopyRect(0, 0, GadgetWidth(Desktop()), GadgetHeight(Desktop()), 0, 0, DesktopBuffer(), ImageBuffer(background))

SetBuffer DesktopBuffer()

Repeat
	
	WaitEvent()
	
	; Update every 1/60 of a second
	If EventSource() = myTimer Then
		
		DrawBlock background, 0, 0
		Text Rand(0, GadgetWidth(Desktop())), Rand(0, GadgetHeight(Desktop())), "This is a test"
		Flip False
		
	EndIf
	
Forever

FreeImage background

And yes, frogs are awesome.