diff --git a/StringUtils.php b/StringUtils.php
index 4b2ef1c..91c287e 100644
--- a/StringUtils.php
+++ b/StringUtils.php
@@ -8,7 +8,7 @@
 
 class StringUtils extends \ExternalModules\AbstractExternalModule {
 
-    const annotation = ["@TOLOWER", "@TOUPPER", "@SUBSTR", "@LTRIM", "@RTRIM", "@TRIM", "@STRLEN", "@INDEXOF"];
+    const annotation = ["@TOLOWER", "@TOUPPER", "@SUBSTR", "@LTRIM", "@RTRIM", "@TRIM", "@STRLEN", "@INDEXOF", "@CONCAT"];
 
 
     public function redcap_data_entry_form($project_id, $record, $instrument, $event_id, $group_id, $repeat_instance)
@@ -58,7 +58,7 @@ public function getFieldNames($project_id)
     public function showWarnings(array $listeners, array $fieldNames, array $warnings)
     {
         foreach ($listeners as $sourceField => $code) {
-            if (!in_array($sourceField, $fieldNames)) {
+            if (!in_array($sourceField, $fieldNames))  {
                 echo '<div class="alert">The following field is used by cannot be found: ' . $sourceField . '</div>';
             }
         }
@@ -123,10 +123,22 @@ public function getListenersFromAnot($field_annotation, $field, $annotation, arr
                     $warnings [] = 'For field: ' . $destinationField . ' ' . $selectedFields[2] . ' is not numeric';
                 }
                 if (!in_array($selectedFields[0], $fieldNames)) {
-                    $warnings [] = 'For field: ' . $destinationField . ' ' . $selectedFields[0] . ' is not fields.';
+                    $warnings [] = 'For field: ' . $destinationField . ' ' . $selectedFields[0] . ' is not a field.';
                 }
                 $listeners[$selectedFields[0]] .= '$("input[name=\'' . $destinationField . '\']").val($("input[name=\'' . $selectedFields[0] . '\']").val().substr(' . $selectedFields[1] . ', ' . $selectedFields[2] . '));';
                 break;
+            case "@CONCAT":
+                $sourceFieldsConcat = [];
+                $explodedSource = explode (",", $sourceField);
+                foreach($explodedSource as $explodedPiece)
+                    {
+                        $sourceFieldsConcat []= "$(\"input[name='$explodedPiece']\").val()";
+                    }
+                foreach($explodedSource as $explodedPiece)
+                {
+                    $listeners[$explodedPiece] .= '$("input[name=\'' . $destinationField . '\']").val('.implode("+",$sourceFieldsConcat).');';
+                }
+                break;
             default:
                 break;
         }
diff --git a/howto.html b/howto.html
index 1e8cec5..3e191fb 100644
--- a/howto.html
+++ b/howto.html
@@ -100,6 +100,14 @@ <h1><span class="glyphicon glyphicon-info-sign"></span> How to use the StringUti
                                     Takes a part of a string from <code>start</code>, returns the specified number of characters (<code>length</code>). <code>start</code> and <code>length</code> must be valid integers.
                                 </td>
                             </tr>
+                            <tr>
+                                <td>
+                                    @CONCAT=field1,field2,field3,...
+                                </td>
+                                <td>
+                                    Concatenates other <b>text</b> fields into one field. The fields must be valid field names. The list can contain any amount of fields. The list of fields MUST NOT contain spaces.
+                                </td>
+                            </tr>
                         </tbody>
                     </table>
                 </div>