Not able to login after an option change

Hi,

I woul like to know which page contains the wordpress url that one sets in the general option page. As I made a mistake by entering an non-existing folder name I’m not able to enter the administration panel to set things straight.
The ‘mistake’ happened because I wanted a page to be my blog homepage with just entering ‘mydomainname/blog’ (not: mydomainname/blog/page_id=4).
I’d like to thank you for taking your time and helping me out on this one.

Mark