--- a/sao/src/view/form.js
+++ b/sao/src/view/form.js
@@ -4415,15 +4418,20 @@ function eval_pyson(value){
             this.el = jQuery('<div/>', {
                 'class': this.class_,
             });
-
+            this.object = null;
+        },
+        create_object: function() {
+            if (this.object) {
+                this.object.remove();
+            }
             this.object = jQuery('<object/>', {
                 'class': 'center-block',
             }).appendTo(this.el);
-            if (attributes.height) {
-                this.object.css('height', parseInt(attributes.height, 10));
+            if (this.attributes.height) {
+                this.object.css('height', parseInt(this.attributes.height, 10));
             }
-            if (attributes.width) {
-                this.object.css('width', parseInt(attributes.width, 10));
+            if (this.attributes.width) {
+                this.object.css('width', parseInt(this.attributes.width, 10));
             }
         },
         display: function() {
@@ -4456,6 +4464,7 @@ function eval_pyson(value){
                     });
                     url = window.URL.createObjectURL(blob);
                 }
+                this.create_object();
                 this.object.attr('data', url);
                 this.object.get(0).onload = function() {