WPC Fly Cart compatible

Hi,

I’m developing WPC Fly Cart, it already supports Instant Checkout on the popup. But it doesn’t work with your plugin because you used the conditon is_checkout() here https://www.screencast.com/t/MTlAblahcBy

Also on the JS file, I think should have a change here https://www.screencast.com/t/hvbPihnGeuoK to make it works with the checkout form that was loaded by AJAX.

Hope you can check and modify your plugin, so it will compatible with other plugins like WPC Fly Cart.

Regards,
Dustin