function popup(windowname,url,width,height,toolbar,returnreference) {
	windowname = windowname.replace('-', '_');
	windowname = windowname.replace('-', '_');
	var RandLinks = (window.screen.availWidth - width)/2;
	var RandOben = (window.screen.availHeight - height)/2;
	win = this.open(url, windowname, "left="+RandLinks+",top="+RandOben+",toolbar="+toolbar+",menubar=no,location=no,scrollbars=no,resizable=no,height="+height+",width="+width);
	win.focus();
	if(returnreference == 1)
		return win;
}