Base URL interfering with FORM Post

[Tanker]

Hello everyone, I'm building a FORM base on certain data from the VM cart..

Say there is no shipment available or there is no payment for X country...
when that happen the Buy now button doesn't show, instead it shows a button that say:
[Request a Quote Now]
so when users click on it, it will send an email...

so my form is very basic:
<form id="quote" method="POST" action="email_quote.php">
</fom>

the email_quote.php file is in the root of joomla installation, but every time I click on that button it sent me to a different location...
BUT!... if I remove the base URL it works fine... so my question is, do I really need the base URL?.. may be yes... in that case, how to do make form to go to the right file? ..


Thank you.