plugin is not compatible with jquery 1.8

[gchokeen]

I am trying create the nested form using this plugin. So I just cloned exact html js in my webpage of this demo. I use jquery 1.8 version. I am getting error like below.

TypeError: nameTemplateAttr is undefined

newNameAttr = nameTemplateAttr.replace(options.indexFormat, index);

Note : I use development veriosion (uncompressed)
Do you have any Idea?

[fadjrin]

replace .attr with .prop,