Action script problem for load swf

I have a website I am creating. The homepage navigation bar has a slider. But now trying to link the navigations buttons to load external swf files I created separately into the main swf using an actionsript function, for some reason it won’t load.

I was trying to use this script on the buttons.

example
on (release) {
_root.contents.loadMovie(“Contact_Us.swf”);
}

The swf is in the same location on my computer.

Does anyone have an idea what might be causing the problem. I am trying to load a scroll bar and some text when the link button is pressed, into the main flash document.