function zoomControl(){
	
	// Refresh tino footer width when zoom in or out
	$('footer-bg').style.width = "100%";
    // move popup message to center screen when users zoom in or out
    if($('popupBackgroundContainer') != null && $('popupBackgroundContainer') != undefined){
    	var contrainerPercent = 210*100/getClientWidth();
    	$('containerPopup').style.left =  eval(50 - contrainerPercent)+ "%";
    }
}

function getClientWidth(){
    var width = document.body.clientWidth;
    if (document.documentElement.scrollWidth > width) {
        width = document.documentElement.scrollWidth;
    }
    if (document.documentElement.clientWidth) {
        width = document.documentElement.clientWidth;
    }
    return width;
}