Resize image

Hi, I am new to actionscript and currently working on a timebar for my project.

However when I wanna reduce the size of the image using actionscript, for example ->

bar._width -= 10;

However the bar will reduce it’s size from 2 ends of it.

Anyone have any ideas of letting the bar to stay put on a location and the bar will reduce it’s size from the right only instead from both left and right?

Or can suggest me any better idea to handle this situation?

Thank you ^^