show form after send

Hello guys,
i know it's a stupid question and i've already done this in the past but now seems that i can't...

I have a simple contact form, all works great, but after submit i receive the email, get the message(sent/notsent) but the form disappear! How to avoid this? the message should be above or below the form, not in its place!

Hope it's clear, if not, sorry for my bad english!
Thanks in advance