eval gzinflate base64_decode PHP Decoder
Remove the PHP tags and just post in the part that looks like:
eval(gzinflate(base64_decode('80jNyclXyFTPVUhJTc5PSU0BAA==')));
Please see the Decoding eval gzinflate thread in the forums for more help.
Script also decodes: eval(gzinflate(str_rot13(base64_decode
Also see php $_F=__FILE__;$_X= Byterun decoder.