diff --git a/js/server/ahuacatl.js b/js/server/ahuacatl.js
index 7436bf667b..2c7c1ac9b9 100644
--- a/js/server/ahuacatl.js
+++ b/js/server/ahuacatl.js
@@ -1235,7 +1235,6 @@ function AHUACATL_MERGE () {
     var element = arguments[i];
 
     if (AHUACATL_TYPEWEIGHT(element) !== AHUACATL_TYPEWEIGHT_DOCUMENT) {
-      print(element);
       throw "expecting documents for merge";
     }
 
@@ -1251,6 +1250,32 @@ function AHUACATL_MERGE () {
   return result; 
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief create the union (all) of all arguments
+////////////////////////////////////////////////////////////////////////////////
+
+function AHUACATL_UNION () {
+  var result = [ ];
+
+  for (var i in arguments) {
+    var element = arguments[i];
+
+    if (AHUACATL_TYPEWEIGHT(element) !== AHUACATL_TYPEWEIGHT_LIST) {
+      throw "expecting lists for union";
+    }
+
+    for (var k in element) {
+      if (!element.hasOwnProperty(k)) {
+        continue;
+      }
+
+      result.push(element[k]);
+    }
+  }
+
+  return result; 
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @}
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/js/server/js-ahuacatl.h b/js/server/js-ahuacatl.h
index 88bb6f08c8..44f3c52f2f 100644
--- a/js/server/js-ahuacatl.h
+++ b/js/server/js-ahuacatl.h
@@ -1236,7 +1236,6 @@ static string JS_server_ahuacatl =
   "    var element = arguments[i];\n"
   "\n"
   "    if (AHUACATL_TYPEWEIGHT(element) !== AHUACATL_TYPEWEIGHT_DOCUMENT) {\n"
-  "      print(element);\n"
   "      throw \"expecting documents for merge\";\n"
   "    }\n"
   "\n"
@@ -1253,6 +1252,32 @@ static string JS_server_ahuacatl =
   "}\n"
   "\n"
   "////////////////////////////////////////////////////////////////////////////////\n"
+  "/// @brief create the union (all) of all arguments\n"
+  "////////////////////////////////////////////////////////////////////////////////\n"
+  "\n"
+  "function AHUACATL_UNION () {\n"
+  "  var result = [ ];\n"
+  "\n"
+  "  for (var i in arguments) {\n"
+  "    var element = arguments[i];\n"
+  "\n"
+  "    if (AHUACATL_TYPEWEIGHT(element) !== AHUACATL_TYPEWEIGHT_LIST) {\n"
+  "      throw \"expecting lists for union\";\n"
+  "    }\n"
+  "\n"
+  "    for (var k in element) {\n"
+  "      if (!element.hasOwnProperty(k)) {\n"
+  "        continue;\n"
+  "      }\n"
+  "\n"
+  "      result.push(element[k]);\n"
+  "    }\n"
+  "  }\n"
+  "\n"
+  "  return result; \n"
+  "}\n"
+  "\n"
+  "////////////////////////////////////////////////////////////////////////////////\n"
   "/// @}\n"
   "////////////////////////////////////////////////////////////////////////////////\n"
   "\n"
diff --git a/js/server/tests/ahuacatl-functions.js b/js/server/tests/ahuacatl-functions.js
index 3db80121a5..3be7ad2226 100644
--- a/js/server/tests/ahuacatl-functions.js
+++ b/js/server/tests/ahuacatl-functions.js
@@ -161,6 +161,37 @@ function ahuacatlFunctionsTestSuite () {
       var actual = getQueryResults("FOR u IN [ { \"id\" : 100, \"name\" : \"John\", \"age\" : 15 }, { \"id\" : 101, \"name\" : \"Corey\", \"age\" : 19 } ] return MERGE(u, { \"id\" : 9 }, { \"name\" : \"foo\", \"id\" : 33 })", false);
       assertEqual(expected, actual);
     },
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief test union function
+////////////////////////////////////////////////////////////////////////////////
+    
+    testUnion1 : function () {
+      var expected = [ [ 1, 2, 3, 1, 2, 3 ], [ 1, 2, 3, 1, 2, 3 ] ];
+      var actual = getQueryResults("FOR u IN [ 1, 2 ] return UNION([ 1, 2, 3 ], [ 1, 2, 3 ])", true);
+      assertEqual(expected, actual);
+    },
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief test union function
+////////////////////////////////////////////////////////////////////////////////
+    
+    testUnion2 : function () {
+      var expected = [ [ 1, 2, 3, 3, 2, 1 ], [ 1, 2, 3, 3, 2, 1 ] ];
+      var actual = getQueryResults("FOR u IN [ 1, 2 ] return UNION([ 1, 2, 3 ], [ 3, 2, 1 ])", true);
+      assertEqual(expected, actual);
+    },
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief test union function
+////////////////////////////////////////////////////////////////////////////////
+    
+    testUnion3 : function () {
+      var expected = [ "Fred", "John", "John", "Amy" ];
+      var actual = getQueryResults("FOR u IN UNION([ \"Fred\", \"John\" ], [ \"John\", \"Amy\"]) return u", true);
+      assertEqual(expected, actual);
+    },
+
   };
 }