var popupCounter = 0;

function popup(url, winName, r_w, r_h, move) {
		if(!r_w) var r_w = 750;
		if(!r_h) var r_h = 550;
		
		if(!winName) var winName = 'popup' + (popupCounter++) + Math.round(Math.random()*100000);
		
		var w_h = screen.availHeight;
		var w_w = screen.availWidth;
		var w_l = (screen.availWidth/2)-(r_w/2) + 20*((popupCounter%6));
		var w_t = (screen.availHeight/2)-(r_h/2) + 20*((popupCounter%6));
		
		if(move){
			w_l += move;
			w_t += move;
		}
		
		var params = "status=no,width=" + r_w + ",height=" + r_h + ", left=" + w_l + ", top="+ w_t + ", resizable=yes";
  		window.open(url,winName,params);
	}