Develloping under PHP4 and APACHE

I am developping a web-site with easyPHP compatible with amaya browser (use of MathML), i don't undestand with when i test it locally and online and when i try to submit a form to MySQL it says "Impossible to submit the form: missing action" whereas it work with MSIE5.
Someone could help me?. I am using v4.3.2
Thank you.