How do I grow and shrink a sprite quickly

I've searched forums but can't seem to find exactly what I need.

I have an object which uses the drag drop behaviour. Once the object is in a certain position, drag drop is disabled and effectively locks the object into place and cannot be moved again, and then plays a sound.

Once the object is locked into position (and drag drop disabled) I want the object to briefly shrink in size (20% of original size) and then grow back to its original size. All done in under one second.

How is this possible?. Here's what my event looks like

every tick > set size > Self.Width-X, Self.Height-X

Thanks, that helped but Is there anyway to actually shrink over x amount of time (0.2 sec), gradually getting smaller to the set size or set scale specified?. Then gradually growing again over 0.2 sec back to original size?.

Otherwise it looks too quick, I want more, smoother movement.

EDIT: Just found the sine behaviour wich seems more what I need. Still can't work out how to shrink the image initially (over 0.2 seconds) and then have it grow back over 0.2 seconds to original size.

Check out the LiteTween plugin. LiteTween