function changeBg(obj,img){
	if(img == ''){
		obj.style.backgroundImage = '';
	}
	else{
		obj.style.backgroundImage = 'url(images/'+img+'_c.jpg)';
	}
} 
function popup(page,width,height){
	var w = window.open(page,'nom','toolbar=0, location=0, directories=0, status=0, scrollbars=1, resizable=1, copyhistory=0, menuBar=0, width='+width+', height='+height+'');
	w.focus();
}