Clicking Button Image without ID

Im wondering how i would click this button image on this website

Mailinator - Let Them Eat Spam!ⓘ

I've tried many ways to do it, but just can't find a soulution..

Anybody know how i would be able to click it?

Thanks in advanced.

Process.start("http://www.mailinator.com/maildir.jsp?email=" & Textbox1.text &"&x=0&y=0")

???