prova a fare una cosa tipo:
codice:
<form name="xxx" action="" method="post">
<input type="text" name="kjhg">

<input type="button" value="pag1" onclick="document.forms[0].action='pag1.htm';document.forms[0].submit();">

<input type="button" value="pag2" onclick="document.forms[0].action='pag2.htm';document.forms[0].submit();">
</form>