var win = null; 

function popup(mypage,myname,w,h,scroll){ 
	// Call with: popup('page.html','window_name','500','340','no');
	var winl = 0;
	var wint = 0;
	winl = (screen.width-w)/2;
	if (navigator.userAgent.indexOf("Opera")==-1){  //Opera needs to be zero as it keeps popups within the browser content area
		wint = (screen.height-h)/2;
	}
	settings='height='+h+',width='+w+',top='+wint+',left='+winl+',scrollbars='+scroll+',toolbar=no,location=no,status=no,menubar=no,resizable=yes,dependent=no' 
	win=window.open(mypage,myname,settings) 
	if(parseInt(navigator.appVersion) >= 4){
		win.window.focus();
	} 
}