HTTP 405 error

form name="AGE_form" enctype="multipart/form-data" action="formmailer.php" method="post"

This is the source code for the form, not all of it but the part I manipulated, I've got on our site, I've manipulated it via Net Objects Fusion which is what I use to develop the site. Everything appears in order but being the newbie I am, I am seeking guidence in the error of my ways. Any help would be appreciated. When I click on the submit button I keep getting the error page, and I am at a loss as to where to go from here. Thank you.