how do i post from one frame to another ?

i want the results of a search in the left frame to load in the main frame.

using the code below, there is nothing happening ?

how do i do that ?

<form name=searchform method=post target="main">
<input type=text name=searchtext action=search>
<input type=hidden name=memberid value=$memberid>
<center><a href=main.php target=main onclick=document.searchform.submit()>Search</a>