var btn_home_link=new Image();
btn_home_link.src='assets/buttons/btn_home_link.png';
var btn_home_over=new Image();
btn_home_over.src='assets/buttons/btn_home_over.png';
var btn_about_link=new Image();
btn_about_link.src='assets/buttons/btn_about_link.png';
var btn_about_over=new Image();
btn_about_over.src='assets/buttons/btn_about_over.png';
var btn_contact_link=new Image();
btn_contact_link.src='assets/buttons/btn_contact_link.png';
var btn_contact_over=new Image();
btn_contact_over.src='assets/buttons/btn_contact_over.png';

function rollOverButtons() {
	var btn_home = document.getElementsByName('btn_home')[0];
	btn_home.onmouseover=rover;
	btn_home.onmouseout=rout;
	var btn_about = document.getElementsByName('btn_about')[0];
	btn_about.onmouseover=rover;
	btn_about.onmouseout=rout;
	var btn_contact = document.getElementsByName('btn_contact')[0];
	btn_contact.onmouseover=rover;
	btn_contact.onmouseout=rout;
	function rover(){	
		btn_rover(this);
	}
	function rout(){	
		btn_rout(this);
	}
	function btn_rover(btn){
		btn.src=eval(btn.name+'_over.src');
	}
	function btn_rout(btn){
		btn.src=eval(btn.name+'_link.src');
	}	
}