code: function(value) {
              value = value || '';
              return this.setStyle({
                  left : value,
                  right : value,
                  top : value,
                  bottom : value,
                  'z-index' : '',
                  position : STATIC
              });
          }
docs: Clears positioning back to the default when the document was loaded.
  @param {String} [value=''] The value to use for the left, right, top, bottom.
  You could use 'auto'.
  @return {Ext.dom.Element} this