Would you please upload YOUR fla file?

At the end of code above you put:

b1.onRelease = function() {

menuSlide(contentHold.content1);
};
b2.onRelease = function() {

menuSlide(contentHold.content2);
};


well, this is why you can only see 2 slide content,

You should put:

b1.onRelease = function() {
menuSlide(contentHold.content1);
};
b2.onRelease = function() {
menuSlide(contentHold.content2);
};
b3.onRelease = function() {
menuSlide(contentHold.content3);
};
b4.onRelease = function() {
menuSlide(contentHold.content4);
};
b5.onRelease = function() {
menuSlide(contentHold.content5);
};


Do you mean that?!