//preload rollover images
if (document.images) {
	home = new Image(46,16); 
	home.src="images/nav_home_over.gif";
	
	samples = new Image(67,16); 
	samples.src="images/nav_samples_over.gif";
	
	who = new Image(36,16); 
	who.src="images/nav_who_over.gif";
	
	why = new Image(35,16); 
	why.src="images/nav_why_over.gif";
	
	what = new Image(40,16); 
	what.src="images/nav_what_over.gif";
	
	when = new Image(45,16); 
	when.src="images/nav_when_over.gif";
	
	contact = new Image(61,16); 
	contact.src="images/nav_contact_over.gif";
}

//function used to create mailto link and hide email addresses from spiders to prevent spam
function mailto(username,domain,class_name){
	var linktext = username + "@" + domain;
	document.write('<a href="' + 'mail' + 'to:' + username + '@' + domain + '" class="'+class_name+'">'+linktext+'</a>');
}