How to reverse a checksum

Ok, this question refers to the javascript 16 challenge and I believe has some good value to ask because could help in other areas as well. I have made a brute forcer and and still trying force the password. But my question is that I know how the password is "encrypted" , I guess you would say, I there any way to feed the checksum back through the "tab" to spit back the password or passwords with the same checksum and that would narrow it down. I am willing to send someone what I have, to someone that completed this challenge or someone that is very close to completing(must have proof to compare). I am coding it in Bloodshed Dev C++ , if that helps, (I do not know if I am aloud to post that , admin please remove if this is a violation to this site.)

Thank you in advanced. -[El Miguel]-