project web site with shindig

[VU, Thi Thu Thuy]

Hi all, 
I created a project website from shindig's code. 
After that, I tried to run examples from this web site. 
(gadget/files/samplecontainer/samplecontainer.html)
But when I debugged it, it appeared an error:
  gadgets.rpc.register('resize_iframe', this.setHeight) is null or not an object

I don't understand much about it.
Could you explain it for me , pls.
Thanks a lot