A responsible applicant
Employer to applicant: "In this job we need someone who is responsible." Applicant: "I'm the one you want. On my last job, every timeanything went wrong, they said I was responsible."

An accountant is having a hard time sleeping...
An accountant is having a hard time sleeping and goes to see his doctor."Doctor, I just can't get to sleep at night." "Have you tried counting sheep?""That's the problem - I make a mistake and then spend three hours trying to find it."