/* checkMail() function used with the permission of the author see:
				http://www.quirksmode.org/js/mailcheck.html
*/
function checkMail(x) {
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(x)) { 
		return true; 
	} else { 	
		alert('Sorry, "'+x+'" is not a valid email address'); 
		return false; 
	}
}

/* Routines for handling nevigation menu elements */
function show(element){
		document.getElementById(element).style.visibility = 'visible';
}
	
function hide(element){
		document.getElementById(element).style.visibility = 'hidden';
}
	
function changeClass(element, newClass){
	document.getElementById(element).className= newClass;
}