Find left/right side of Movieclip

Hi All,

Can anyone tell me if there is a way with actionscript to determine the right and left side of a movie clip? I have a row of dynamiclly loaded pictures that load into a movieclip and then have arrows that scroll the photos left and right using an interval and _x +=10. The scroll works great. Only problem is, it just goes on and on and on if you keep pressing the arrow. Is there any way to tell it where the left and right side are and not to let either side go past a certain point. sorry for the long winded question.

thanks in advance!