Cross refence images In-Tools Scripts Forum

I have tried this script in Indesign CS5:

var name  = prompt("Pick a name","","Create anchor in graphic frame");
if(name){
    makeObjectAnchor(app.selection[0],name);
}
function makeObjectAnchor(object,destinationName){
    var tf = object.textFrames.add();
    app.documents[0].hyperlinkTextDestinations.add(tf.parentStory.insertionPoints[0],{name:destinationName});
}

The thing is that I end up with <PB> instead of the real page number in the source text...
In the cross-references panel, I have PB written in red and it says "Invalid destination: on the pasteboard"
Can someone help please?