[shizzlest]

No answer is as bad as the truth or a lie.

how about " Well, I did apply to your company to improve, so we should rather have a conversation about the money I expect than what I currently have. Here is what I want to get paid [insert number 20% higher than what you really would settle for].... Does it fit into your range ? "

That gives enough room but also leaves enough chance to go on in the interview. Remind yourself that getting a job at a price that you set by yourself is better than being afraid of loosing out the opportunity to max out to the limit. Good staff always gets a second chance !