Complete web purchase from message (bug 1101995)

@muffinresearch r?

I've only tested with a dummy html page but it should work with your patch!
Looks ok to me from this http://jsbin.com/nogici/1/edit?html,js,console
![origin-bin](https://cloud.githubusercontent.com/assets/1514/5469254/5bab753c-85d1-11e4-9386-167544c931fc.png)