Actionscript trouble

For some reason this code isn’t working for me. i have my buttons named button1MC-button5MC. The onRelease code for them is:
button1MC.onRelease = function () {
if(whoIsOn != this) {
whoIsOn.gotoAndPlay(15);
whoIsOn = this;
navigate(this._name);
}
}

navigation function is here:

_global.navigate = function(x) {
_global.pressed = x;
if (pressed != already) {
_global.already = pressed;
name = String(x);
which = name.charAt(6);
contentMc.section = String(“section”+which);
contentMc.play();
}
}

nothing happens when i click the buttons, any help would be great.