var posit=min_pos=2;
var max_pos=4;
function listing(name) {
	var My_Swift = document.getElementById('content');
	if (name=='left') {
		if (posit==min_pos) posit=max_pos+1; 
		posit-=1;
	}
	else {
		if (posit==max_pos) posit=min_pos-1;
		posit+=1;
	}
	My_Swift.style.background="url('/bitrix/templates/template_1/img/"+posit+".jpg') right top no-repeat";
	return false;
}