Trouble with if/else statement

I’m trying to right some script that says when a user rolls over this button it should go to the 2nd frame (visible, 1st frame is empty) of a particular movieclip. But I want to be sure that none of the other movieclips on the stage are showing, so I wrote this if/else statement to say that if the currentframe of the other movieclip is 1 (not showing) then go stop on the 2nd frame of this movieclip. If not, go stop on frame 1 of the other movieclip and then go stop on frame 2 of this movie clip. Here is the code below. Someone please tell me why it’s not working. I have the code on the instance of the button. The button and both movie clips are on the main stage.

on (rollOver) {
if (_root.insured_mc._currentframe=1) {
polNum_mc.gotoAndStop(2);
} else {
_root.insured_mc.gotoAndStop(1);
polNum_mc.gotoAndStop(2);
}
}

When I publish the SWF, i make sure that insured_mc is on frame 2, to test the code, then I rollover the button in question and polNum_mc goes to the 2nd frame too, but insured_mc doesn’t turn off (go to frame 1).