Email Link

I am new to action script 3.0 and I am trying to build a site. I have a contact button on the site that leads to a contacts page where I have provided emails that you can click on to email that person. However I have written the code for it and it only works if the link is on the home page but it doesn’t work if I have it on the contact page. I need help with this. Here is my code. It keeps giving me a TypeError: Error #1009: Cannot access a property or method of a null object reference. MainTimeline/frame1()[Omega_Seminars_fla.MainTimeline::frame1:15]

var loisMail_req:URLRequest = new URLRequest("mailto:address@somewhere.net");

contact_btn.addEventListener(MouseEvent.CLICK, contact);
function contact(event:MouseEvent):void
{
gotoAndPlay(“Contact”);
}

mail.addEventListener(MouseEvent.CLICK, mailLink);
function mailLink(event:MouseEvent):void
{
navigateToURL(loisMail_req, “_blank”);
}