Math.round question

I’m using this code on an empty container which loads content from an external swf. I added the Math.round so that when the container slides the pixel font stays clear.

onClipEvent (load) {
Xpos = 170;
}
onClipEvent (enterFrame) {
Xa = _root.container1._x;
Xdiff = Xpos-Xa;
Xmove = Xdiff/7;
_root.container1._x = Math.round(Xa+Xmove);
}

The problem is that now the slide stops or too early or too late of a pixel, enough for not aligning with the rest of the elements on the page.
Is there a way that if Xa+Xmove = 17.2 it goes 17 (normal Math.round)and instead if Xa+Xmove = 17.8 it goes 18?
:flower: