Suppose you have your object Label1 in a container try this with a timer.Set the timer interval to 10. Just try it might work.

if This.Parent.Container1.Label1.left<>(This.Parent.Container1.Label1.width)*-1
This.Parent.Container1.Label1.left=This.Parent.Container1.Label1.left-1
endif
if This.Parent.Container1.Label1.left=(This.Parent.Container1.Label1.width)*-1
This.Parent.Container1.Label1.left=This.Parent.Container1.width
endif