Set image offset?

I was searching on the forums for a way to animate my background a bit, and I heard about this function in Construct Classic. I noticed that it's missing in C2..

In my case, I'm making a lava pit and would like the lava to slowly move to the right, but I didn't want to create an sprite object for that sole purpouse.

Any good ways of doing this? It would add so much to the level, lava just doesn't feel the same when it's stopped...

Here's a picture:

<img src="http://i.imgur.com/DDuEW.jpg" border="0" />

Maybe something like this?

http://dl.dropbox.com/u/5426011/examples12/lava.capx

Exactly like that! You just helped me with 2 things actually, I wanted to know how create masks like that for the item menu I'm thinking too!

Thanks a lot!!