function shareOnFacebook($url) {
	var url = 'http://www.facebook.com/sharer.php?u='+encodeURI($url);
	popup(url);
}

function shareOnTwitter($url, $text) {
	var url = 'http://twitter.com/share?url='+encodeURI($url)+'&text='+encodeURI($text);
	popup(url);
}

function popup(url) {
	var width  = 600;
	var height = 400;
	var left   = (screen.width  - width)/2;
	var top    = (screen.height - height)/2;
	var params = 'width='+width+', height='+height;
	params += ', top='+top+', left='+left;
	params += ', directories=no';
	params += ', location=no';
	params += ', menubar=no';
	params += ', resizable=no';
	params += ', scrollbars=no';
	params += ', status=no';
	params += ', toolbar=no';
	win=window.open(url,'window', params);
	if (window.focus) {win.focus()}
	return false;
}