diff --git a/imagefield_crop.js b/imagefield_crop.js
index eb3a385..53ba564 100644
--- a/imagefield_crop.js
+++ b/imagefield_crop.js
@@ -28,10 +28,35 @@ Drupal.behaviors.imagefield_crop = {
         // get the name attribute for imagefield name
         var widget = self.parent().parent();
 
-          if ($(".edit-image-crop-changed", widget).val() == 1) {
-              $('.preview-existing', widget).css({display: 'none'});
-              $('.jcrop-preview', widget).css({display: 'block'});
+        if ($(".edit-image-crop-changed", widget).val() == 1) {
+          $('.preview-existing', widget).css({display: 'none'});
+          $('.jcrop-preview', widget).css({display: 'block'});
+        }
+          
+        // -- only change select arguments for jcrop if they are the default ones // FIXME
+        if (parseInt($(widget).siblings(".edit-image-crop-x").val()) == 0 && parseInt($(widget).siblings(".edit-image-crop-x").val()) == 0 && parseInt($(widget).siblings(".edit-image-crop-width").val()) == 50 && parseInt($(widget).siblings(".edit-image-crop-height").val()) == 50) {
+          // -- set default crop size
+          var selectHeight = 0;
+          var selectWidth = 0;
+          var selectOffsetX = 0;
+          var selectOffsetY = 0;
+          // calculate max. init box width and height
+          if (Drupal.settings.imagefield_crop[id].preview.orig_width > Drupal.settings.imagefield_crop[id].preview.orig_height) {
+            selectHeight = Drupal.settings.imagefield_crop[id].preview.orig_height;
+            selectWidth = Drupal.settings.imagefield_crop[id].preview.orig_height * Drupal.settings.imagefield_crop[id].box.ratio;
+            selectOffsetX = (Drupal.settings.imagefield_crop[id].preview.orig_width - selectWidth)/2;
           }
+          else {
+            selectWidth = Drupal.settings.imagefield_crop[id].preview.orig_width;
+            selectHeight = Drupal.settings.imagefield_crop[id].preview.orig_width * Drupal.settings.imagefield_crop[id].box.ratio;
+            selectOffsetY = (Drupal.settings.imagefield_crop[id].preview.orig_height - selectHeight)/2;
+          }
+          // overwrite default values
+          $(widget).siblings(".edit-image-crop-x").val(selectOffsetX);
+          $(widget).siblings(".edit-image-crop-y").val(selectOffsetY);
+          $(widget).siblings(".edit-image-crop-width").val(selectWidth);
+          $(widget).siblings(".edit-image-crop-height").val(selectHeight);
+        }
 
         $(this).Jcrop({
           onChange: function(c) {