Arranging movie clips

programming flash
1

I have created four menus and have placed in cascading style (ie. overlaping one after another, showing partially the below one), Now I want each menu come above (front)when I click it, (ie, when I click the second, third or the fourth menu, it should come above in 1st place and the 1st menu should get below it). Please let me know how to do this in using actionscript 2.0.

Amit

2 
function swap () {
 this.swapDepths(this._parent.getNextHighestDepth());
}
a_mc.onRelease=b_mc.onRelease=c_mc.onRelease=d_mc.onRelease=swap;