center infobox on screen

functions.js

@@ -868,3 +868,20 @@ function leading_zero(p) {
 	if (s.length == 1) s = "0" + s;
 	return s;
 }
+
+function center_element(e) {
+	var c_width = document.body.clientWidth;
+	var c_height = document.body.clientHeight;
+
+	var c_scroll = document.body.scrollTop;
+
+	var e_width = e.clientWidth;
+	var e_height = e.clientHeight;
+
+	var set_y = (c_height / 2) + c_scroll - (e_height / 2);
+	var set_x = (c_width / 2) - (e_width / 2);
+
+	e.style.top = set_y + "px";
+	e.style.left = set_x + "px";
+	
+}

prefs.js

@@ -149,11 +149,11 @@ function infobox_callback() {
 	if (xmlhttp.readyState == 4) {
 		var box = document.getElementById('infoBox');
 		var shadow = document.getElementById('infoBoxShadow');
-
-		if (box) {
-			box.innerHTML=xmlhttp.responseText;
+		if (box) {			
+			box.innerHTML=xmlhttp.responseText;			
 			if (shadow) {
 				shadow.style.display = "block";
+				center_element(shadow);
 			} else {
 				box.style.display = "block";				
 			}

tt-rss.css

@@ -554,11 +554,9 @@ div.helpResponse {
 #infoBoxShadow {
 	background-image : url("images/shadow.png");
 	position : absolute;
-	margin-left : 30%;
 	width : 30%;
 	z-index : 3;
 	display : none;
-	top : 30%;
 }
 
 div.infoBoxContents {