function isValidEmail(email) {
	var filter = /^([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;
	if (!filter.test(email)) {
		return false;
	} else {
		return true;
	}
}

function isValidUsername(username) {
	var pattern = /^[a-zA-Z0-9_]{4,}$/;
	if (!pattern.test(username)) {
		return false;
	} else {
		return true;
	}
}

var loadingTimer, loadingFrame = 1;

function showLoadingAnimation(){
	$j("#globalOverlay").height($j(document).height());
	loadingTimer = setInterval(animateLoader, 66);
	$j('#globalOverlay').show();
	$j('#ajaxLoading').show();
}
	
function hideLoadingAnimation(){
	$j('#ajaxLoading').hide();	
	$j('#globalOverlay').hide();
	clearInterval(loadingTimer);
}

function animateLoader() {
	if (!$j('#ajaxLoading').is(':visible')){
		clearInterval(loadingTimer);
		return;
	}

	$j('#ajaxLoading').css('background', 'url("/resources/admin/js/global/fancybox/fancy_loading.png") 0px ' + (loadingFrame * -40) + 'px');
	
	loadingFrame = (loadingFrame + 1) % 12;
};