Retaining image size in Threaded frames during Relink

Hi,

I tried to relink my images without changing its frame size using

      var guid = graphicItems.parent.associatedXMLElement.xmlAttributes.itemByName("product_id").value;

    var guidval = "tb" + guid + "G" + g + "TF" + myCounter;

    var currObj = eval(myDocument.extractLabel(guidval));

             graphicItems.parent.resize(CoordinateSpaces.innerCoordinates, AnchorPoint.centerAnchor,

         ResizeMethods.REPLACING_CURRENT_DIMENSIONS_WITH, [currObj[3] - currObj[1], currObj[2] - currObj[0]]);

This worked for me in unlinked frames.When I tried to relink my images in linked frames this script failed for me. I received my currObj  value as undefined for images in unlinked frames.What should be done to to relink my images with the same frame size in linked frames?

Thanks and Regards,

Revathi V