Tried to fiddle with search form, now I get the white screen after I configure anything!

I was trying to fiddle with my search form and get rid of the "search my site" text so I could label it differently in the block. However, after numerous unsuccessful attempts to follow different instructions on how to do this, I seem to have broken something. My site is still working OK, but after I change any settings on my site, I get the white screen. It always makes the change, but I have to return to my homepage to get going again.

I tried reinstalling the search module, and that hasn't helped. Other pages I may have affected include my theme's template/css files.

HELP??!!