I have recently installed WordPress and was trying out some different themes and installed one that had no way to change anything, i.e. there was no meta link or anyway to get in and change it to some other theme. I erased the theme from the directory hoping that it would default to one of the others. It did not. Now when I try to access the blog it is just a blank page. The only themes I have in the system now is the two that come with wordpress and one other. How can I get a theme back into wordpress?