mouse events X coordinates

Hello

How would I scale an image using the X coordinates? I don't want to shrink the image. The effect I'm going for would be... When the mouse is in the middle of the stage you would only be able to see half of the image and as the mouse is moved to the left you can see more of the image, and as the mouse is moved to the right, you can see less of the image. How can I do this? Thanks in advance

Well I think I got it.... transformed image to movie clip and inside the movie clip inserted new layer on top as a mask and gave instance name. Used the mask to cover up the actual image and follow the mouse on x coordinate unmasking and masking as mouse moves