IE Click Button without Name or ID

Hello!

I seem to be having an issue trying to click a button. The whole goal is to login to the website listed below.

https://service.ariba.com/Supplier.aw/691728/aw?awh=r&awssk=XNwakvnQ&dard=1

For some reason, I'm unable to find a way to click the button as the button doesnt have a name or ID and I've been trying to to figure out how to use the TAG IE functions to my advantage, but to no avail. The button has a unique class name (i believe) "btnC".

Does anyone know a way to submit the login form?

Any help is appreciated.

Thanks!

Michael