How can I get gmail to cancel an email instead of always placing it in drafts?

[Hairyback]

In Gmail, I will often reply to an email, start typing, then change my mind.
So I click inbox (to cancel the message and return to the inbox), and get the following dialog:
Your message has not been sent.
Discard your message?
...cancel ...ok

if I click ok it automatically saves those changes in drafts, rather than canceling them
is there an easy way to dispose of the message.
its irritating to have to go into drafts and clear them all the time.