function get_top_left(width, height){
	if (parseInt(navigator.appVersion)>3) {
		if (navigator.appName=="Netscape") {
	  		winW = window.innerWidth;
	  		winH = window.innerHeight;
	 		winL = window.screenX;
	 		winT = window.screenY;
	 	}else{
	 	//if (navigator.appName.indexOf("Microsoft")!=-1) {
	  		winW = document.body.offsetWidth;
	  		winH = document.body.offsetHeight;
	  		winL = window.screenLeft;
	  		winT = window.screenTop;
	 	}
	}
	
	var scroll = 0;
	var l = winL + winW/2 - width/2;
	var t = winT + winH/2 - height/2;
	
	
  	if(screen.width <= width){
  		width=screen.width;
  	}
  	if(screen.height <= height){
  		height=screen.height;
 	 	var t = 0;
  		var scroll = 1;
  	}
	return Array(t,l);
}

/* generic window opener */
function openwin(uri,title,w,h){
	if(w){wwidth = w;}else{	wwidth = 380;}
	if(h){wheight = h; }else{ wheight = 380;}
	xy = get_top_left(wwidth, wheight);
	wleft = xy[1];
	wtop = xy[0];
	wnd = window.open(uri, title, "width="+wwidth+", height="+wheight+", left="+wleft+", top="+wtop+", toolbar=no, location=no, scrollbars=yes, status=no, menubar=no, resizable=no, directories=no");
}

/* mouse overs */
function toggle_mouseover(obj, file_ext) {
	var source = obj.src
	if (source.indexOf('_over.'+file_ext) > -1) {
		obj.src = source.replace('_over.'+file_ext, '.'+file_ext);
	} else {
		obj.src = source.replace('.'+file_ext, '_over.'+file_ext);
	}
}