Fatal error: common.inc(1342) : eval()'d code:22)

I've just installed DRUPAL. It's the best CMS that I've work with... well, actually the only one I got to understand so well. It's so easy.
But, I knew life could't be all that good!

I came across this problem: I was trying to create a block, and somehow things didn't work out when I tried to save it.
This is my error message:

Fatal error: Cannot redeclare getimageslist() (previously declared in C:\Program Files\xampp\htdocs\CMS\DRUPAL\includes\common.inc(1342) : eval()'d code:22) in C:\Program Files\xampp\htdocs\CMS\DRUPAL\includes\common.inc(1342) : eval()'d code on line 28

Anybody who can give me some wise info & help me please? What do I do!?!?!?

Thanking you,