Menu bar triggered by mouse position--please help me!

1

My code is below. What am I doing wrong? I am trying to have my menu enter the stage and exit the stage when the mouse goes below/above a certain point (425px). I could really use someone’s help.

navBar == 0;

Mouse.addListener(listener);

if(_ymouse >= 425){
 trace("hi");
 navBar_mc.gotoAndPlay("intro");
navBar == 1;

}
else{
if ( _ymouse <= 425 && navBar == 1) {
navBar_mc.gotoAndPlay(“exit”);
navBar == 0;
}
}