stay logged on as admin?

Is there a way to stay logged on as a admin?
I am afraid that I won’t ba able to log on again after 10 days (like last time). I don’t want to put a new site online again and again. Is there a way to stay logged on as a admin for longer than 10 gays? Or maybe there is an other way to acces the admin pages. I made some mistake in the code I guess. I can’t register, it just shows a blank page istead op remembering that I just filled in my login and password. I think it isn’t a mistake in wordpress because I installed it again, and I think I will have the same problem now.
Is this a cookie problem?

Please help me.

Site: http://www.mingei.be/home (under construction)