NEVER mention you have asperger's in an interview.
Asperger's is a disability and most employers are prejudice against disabilities, even if you get the 1% who are not prejudice or who are specifically looking to fill their disability quota for equal opportunities, it's still too high a risk. Employers are spoiled for choice, rather than looking for the best person for the job a large part of the application/interview process is about them finding excuses to drop you out of the running for the job, a disability (even one that is not a disability in your case, or one that makes you better suited for a role) is an excuse to rule you out. It's sad, but there it is...even with so-called 'equal opportunity employers'.
Possibly inform them once you have the job.
I say 'possibly' because if an employer is prejudice they may find an excuse to let you go based on this, they can't outright say that you're fired because of having asperger's but then can always say you're not suited to the role or find another excuse to get rid of you. Only inform them of being an aspie if it causes problems in work - major problems only, for example don't let them know you have asperger's just because it's making it hard to socialise with co-workers...unless this issue with socialisation may be reason to fire you.
The only exception to the rule is with guaranteed interview schemes.
Not sure if you have this where you are, it's also not available for all employers (watch out for it on application forms) - the scheme is that if you're disabled they guarantee you an interview. This can backfire too, but if you find you're not getting anywhere for a while during job searching this can be useful because it gets you in the door, although you're letting them know you have a disability at the same time you're able to sell yourself, deal with any concerns they have and they get to fill their disabled quota with someone with a lesser disability.
_________________
Bloodheart
Good-looking girls break hearts, and goodhearted girls mend them.