diff --git a/backend.php b/backend.php
index 327030e32..0ee60a3f8 100644
--- a/backend.php
+++ b/backend.php
@@ -1726,6 +1726,58 @@
 
 		$subop = $_GET["subop"];
 
+		if ($subop == "test") {
+
+			$expr = $_GET["expr"];
+			$descr = $_GET["descr"];
+
+			print "<div class='infoBoxContents'>";
+		
+			print "<h1>Label &laquo;$descr&raquo;</h1>";
+
+//			print "<p><b>Expression</b>: $expr</p>";
+
+			$result = db_query($link, 
+				"SELECT count(id) AS num_matches
+					FROM ttrss_entries,ttrss_user_entries
+					WHERE ($expr) AND 
+						ttrss_user_entries.ref_id = ttrss_entries.id AND
+						owner_uid = " . $_SESSION["uid"]);
+
+			$num_matches = db_fetch_result($result, 0, "num_matches");;
+			
+			if ($num_matches > 0) { 
+
+				print "<p>Query returned <b>$num_matches</b> matches, first 5:</p>";
+
+				$result = db_query($link, 
+					"SELECT title, 
+						(SELECT title FROM ttrss_feeds WHERE id = feed_id) AS feed_title
+					FROM ttrss_entries,ttrss_user_entries
+							WHERE ($expr) AND 
+							ttrss_user_entries.ref_id = ttrss_entries.id
+							AND owner_uid = " . $_SESSION["uid"] . " 
+							ORDER BY date_entered DESC LIMIT 5");
+
+				print "<ul class=\"nomarks\">";
+				while ($line = db_fetch_assoc($result)) {
+					print "<li>".$line["title"].
+						" <span class=\"insensitive\">(".$line["feed_title"].")</span></li>";
+				}
+				print "</ul>";
+
+			} else {
+				print "<p>Query didn't return any matches.</p>";
+			}
+
+			print "</div>";
+
+			print "<div align='center'>
+				<input type='submit' class='button'			
+				onclick=\"closeInfoBox()\" value=\"Close this window\"></div>";
+			return;
+		}
+
 		if ($subop == "editSave") {
 
 			$sql_exp = $_GET["s"];
@@ -1780,6 +1832,8 @@
 				owner_uid = ".$_SESSION["uid"]."
 			ORDER by description");
 
+		print "<div id=\"infoBoxShadow\"><div id=\"infoBox\">PLACEHOLDER</div></div>";
+
 		if (db_num_rows($result) != 0) {
 
 			print "<p><table width=\"100%\" class=\"prefLabelList\" id=\"prefLabelList\">";
@@ -1859,6 +1913,8 @@
 	
 			if ($subop == "edit") {
 				print "Edit label:
+					<input type=\"submit\" class=\"button\" 
+						onclick=\"javascript:labelTest()\" value=\"Test\">
 					<input type=\"submit\" class=\"button\" 
 						onclick=\"javascript:labelEditCancel()\" value=\"Cancel\">
 					<input type=\"submit\" class=\"button\" 
diff --git a/prefs.js b/prefs.js
index 04b313836..c000ca19b 100644
--- a/prefs.js
+++ b/prefs.js
@@ -706,6 +706,19 @@ function feedEditSave() {
 
 }
 
+function labelTest() {
+
+	var sqlexp = document.getElementById("iedit_expr").value;
+	var descr = document.getElementById("iedit_descr").value;
+
+	xmlhttp.open("GET", "backend.php?op=pref-labels&subop=test&expr=" +
+		param_escape(sqlexp) + "&descr=" + param_escape(descr), true);
+
+	xmlhttp.onreadystatechange=infobox_callback;
+	xmlhttp.send(null);
+
+}
+
 function labelEditCancel() {
 
 	if (!xmlhttp_ready(xmlhttp)) {
diff --git a/tt-rss.css b/tt-rss.css
index 5e598f714..6d682a1b3 100644
--- a/tt-rss.css
+++ b/tt-rss.css
@@ -657,3 +657,7 @@ div.logoutContent {
 	margin-top : 20px;
 	padding : 10px;
 }
+
+.small {
+	font-size : small;
+}