diff --git a/functions.js b/functions.js
index 683d80077..209ca340a 100644
--- a/functions.js
+++ b/functions.js
@@ -404,26 +404,7 @@ function setActiveFeedId(id) {
 	return setCookie("ttrss_vf_actfeed", id);
 }
 
-var xmlhttp_rpc = false;
-
-/*@cc_on @*/
-/*@if (@_jscript_version >= 5)
-// JScript gives us Conditional compilation, we can cope with old IE versions.
-// and security blocked creation of the objects.
-try {
-	xmlhttp_rpc = new ActiveXObject("Msxml2.XMLHTTP");
-} catch (e) {
-	try {
-		xmlhttp_rpc = new ActiveXObject("Microsoft.XMLHTTP");
-	} catch (E) {
-		xmlhttp_rpc = false;
-	}
-}
-@end @*/
-
-if (!xmlhttp_rpc && typeof XMLHttpRequest!='undefined') {
-	xmlhttp_rpc = new XMLHttpRequest();
-}
+var xmlhttp_rpc = Ajax.getTransport();
 
 function parse_counters(reply, f_document, title_obj, scheduled_call) {
 	try {
@@ -937,27 +918,6 @@ function leading_zero(p) {
 	return s;
 }
 
-function center_element(e) {
-
-	try {
-		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";
-	} catch (e) {
-		exception_error("center_element", e);
-	}
-}
-
 function closeInfoBox() {
 	var box = document.getElementById('infoBox');
 	var shadow = document.getElementById('infoBoxShadow');
diff --git a/prefs.js b/prefs.js
index c98dbcc8d..23830cee7 100644
--- a/prefs.js
+++ b/prefs.js
@@ -11,24 +11,7 @@ var feed_to_expand = false;
 var piggie_top = -400;
 var piggie_fwd = true;
 
-/*@cc_on @*/
-/*@if (@_jscript_version >= 5)
-// JScript gives us Conditional compilation, we can cope with old IE versions.
-// and security blocked creation of the objects.
-try {
-	xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
-} catch (e) {
-	try {
-		xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
-	} catch (E) {
-		xmlhttp = false;
-	}
-}
-@end @*/
-
-if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
-	xmlhttp = new XMLHttpRequest();
-}
+var xmlhttp = Ajax.getTransport();
 
 function expand_feed_callback() {
 	if (xmlhttp.readyState == 4) {
@@ -476,38 +459,6 @@ function getSelectedFeedsFromBrowser() {
 	return selected;
 }
 
-
-/*function readSelectedFeeds(read) {
-
-	if (!xmlhttp_ready(xmlhttp)) {
-		printLockingError();
-		return
-	}
-
-	var sel_rows = getSelectedFeeds();
-
-	if (sel_rows.length > 0) {
-
-		if (!read) {
-			op = "unread";
-		} else {
-			op = "read";
-		}
-
-		notify("Marking selected feeds as " + op + "...");
-
-		xmlhttp.open("GET", "backend.php?op=pref-rpc&subop=" + op + "&ids="+
-			param_escape(sel_rows.toString()), true);
-		xmlhttp.onreadystatechange=notify_callback;
-		xmlhttp.send(null);
-
-	} else {
-
-		alert("No feeds are selected.");
-
-	}
-} */
-
 function removeSelectedLabels() {
 
 	if (!xmlhttp_ready(xmlhttp)) {
@@ -719,8 +670,6 @@ function feedCatEditSave() {
 
 	notify("Saving category...");
 
-//	var cat_title = document.getElementById("iedit_title").value;
-
 	var query = Form.serialize("feed_cat_edit_form");
 
 	xmlhttp.open("GET", "backend.php?" + query, true);
diff --git a/tt-rss.js b/tt-rss.js
index 6a3171469..99afd7d6e 100644
--- a/tt-rss.js
+++ b/tt-rss.js
@@ -11,24 +11,7 @@ var firsttime_update = true;
 var last_refetch = 0;
 var cookie_lifetime = 0;
 
-/*@cc_on @*/
-/*@if (@_jscript_version >= 5)
-// JScript gives us Conditional compilation, we can cope with old IE versions.
-// and security blocked creation of the objects.
-try {
-	xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
-} catch (e) {
-	try {
-		xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
-	} catch (E) {
-		xmlhttp = false;
-	}
-}
-@end @*/
-
-if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
-	xmlhttp = new XMLHttpRequest();
-}
+var xmlhttp = Ajax.getTransport();
 
 function toggleTags() {
 	display_tags = !display_tags;
diff --git a/tt-rss.php b/tt-rss.php
index d0a31f6bb..8f7c1d476 100644
--- a/tt-rss.php
+++ b/tt-rss.php
@@ -44,6 +44,8 @@
 
 	<? } ?>
 
+	<script type="text/javascript" src="prototype.js"></script>
+
 	<script type="text/javascript" src="tt-rss.js?<?= $dt_add ?>"></script>
 	<script type="text/javascript" src="functions.js?<?= $dt_add ?>"></script>
 	<!--[if gte IE 5.5000]>