diff --git a/file_entity.pages.inc b/file_entity.pages.inc
index bb61c48..d892302 100644
--- a/file_entity.pages.inc
+++ b/file_entity.pages.inc
@@ -333,10 +333,13 @@ function file_entity_add_upload_submit($form, &$form_state) {
 
   // This var is set to TRUE when we are ready to save the file.
   $save = FALSE;
-  $trigger = $form_state['triggering_element']['#id'];
+
+  // Form id's can vary depending on how many other forms are displayed, so we
+  // need to do find the string part of it. e.g submit from edit-submit--2.
+  list(,$trigger,) = explode('-', $form_state['triggering_element']['#id'], 3);
 
   $steps_to_check = array(2, 3);
-  if ($trigger == 'edit-previous') {
+  if ($trigger == 'previous') {
     // If the previous button was hit,
     // the step checking order should be reversed 3, 2.
     $steps_to_check = array_reverse($steps_to_check);
@@ -344,7 +347,7 @@ function file_entity_add_upload_submit($form, &$form_state) {
 
   foreach ($steps_to_check as $step) {
     // Check if we can skip step 2 and 3.
-    if (($form['#step'] == $step - 1 && $trigger == 'edit-next') || ($form['#step'] == $step + 1 && $trigger == 'edit-previous')) {
+    if (($form['#step'] == $step - 1 && $trigger == 'next') || ($form['#step'] == $step + 1 && $trigger == 'previous')) {
       $file = file_load($form_state['storage']['upload']);
       if ($step == 2) {
         // Check if we can skip step 2.
@@ -353,12 +356,12 @@ function file_entity_add_upload_submit($form, &$form_state) {
           $candidates_keys = array_keys($candidates);
           // There is only one possible filetype for this file.
           // Skip the second page.
-          $form['#step'] += ($trigger == 'edit-previous') ? -1 : 1;
+          $form['#step'] += ($trigger == 'previous') ? -1 : 1;
           $form_state['storage']['type'] = reset($candidates_keys);
         }
         elseif (!$candidates || variable_get('file_entity_file_upload_wizard_skip_file_type', FALSE)) {
           // Do not assign the file a file type.
-          $form['#step'] += ($trigger == 'edit-previous') ? -1 : 1;
+          $form['#step'] += ($trigger == 'previous') ? -1 : 1;
           $form_state['storage']['type'] = FILE_TYPE_NONE;
         }
       }
@@ -374,17 +377,17 @@ function file_entity_add_upload_submit($form, &$form_state) {
 
         if (!file_entity_file_is_writeable($file)) {
           // The file is read-only (remote) and must use its provided scheme.
-          $form['#step'] += ($trigger == 'edit-previous') ? -1 : 1;
+          $form['#step'] += ($trigger == 'previous') ? -1 : 1;
           $form_state['storage']['scheme'] = file_uri_scheme($file->uri);
         }
         elseif (count($schemes) == 1) {
           // There is only one possible stream wrapper for this file.
           // Skip the third page.
-          $form['#step'] += ($trigger == 'edit-previous') ? -1 : 1;
+          $form['#step'] += ($trigger == 'previous') ? -1 : 1;
           $form_state['storage']['scheme'] = key($schemes);
         }
         elseif (variable_get('file_entity_file_upload_wizard_skip_scheme', FALSE)) {
-          $form['#step'] += ($trigger == 'edit-previous') ? -1 : 1;
+          $form['#step'] += ($trigger == 'previous') ? -1 : 1;
 
           // Fallback to the URI scheme specified in the field settings
           // otherwise use the default file scheme.
@@ -400,7 +403,7 @@ function file_entity_add_upload_submit($form, &$form_state) {
   }
 
   // We have the filetype, check if we can skip step 4.
-  if (($form['#step'] == 3 && $trigger == 'edit-next')) {
+  if (($form['#step'] == 3 && $trigger == 'next')) {
     $file = file_load($form_state['storage']['upload']);
     if (!field_info_instances('file', $form_state['storage']['type'])) {
       // This filetype doesn't have fields, save the file.
@@ -412,15 +415,13 @@ function file_entity_add_upload_submit($form, &$form_state) {
     }
   }
 
-  // Form id's can vary depending on how many other forms are displayed, so we
-  // need to do string comparissons. e.g edit-submit--2.
-  if (strpos($trigger, 'edit-next') !== FALSE) {
+  if ($trigger == 'next') {
     $form_state['step'] = $form['#step'] + 1;
   }
-  elseif (strpos($trigger, 'edit-previous') !== FALSE) {
+  elseif ($trigger == 'previous') {
     $form_state['step'] = $form['#step'] - 1;
   }
-  elseif (strpos($trigger, 'edit-submit') !== FALSE) {
+  elseif ($trigger == 'submit') {
     $save = TRUE;
   }