closetime = 180; 

function Start(URL, WIDTH, HEIGHT) {
windowprops = "left=50,top=50,width=" + WIDTH + ",height=" + HEIGHT;
preview = window.open(URL, "preview", windowprops);
if (closetime) setTimeout("preview.close();", closetime*1000);
}

function doPopup() {
url = "popup/popup.php";
width = 700;  
height = 600; 
delay = 1;    
timer = setTimeout("Start(url, width, height)", delay*10);
}