[TYPO3] Form action --> $HTTP_GET_VARS does not get variable

[typo3 at net-products.nl]

Hello,

I wrote a page in typo with php code.

This form has to open another page also with php code. In that page a quiry
is run

But the problem is that if the page is sumbmit:
http://typo3.deleukstestofzuiger.nl/index.php?postcode=11&submit=zoek

but when I manually write
http://typo3.deleukstestofzuiger.nl/index.php?id=77?postcode=11&submit=zoek

there is also no result.

But when I direct submit
http://typo3.deleukstestofzuiger.nl/output.php?postcode=11&submit=zoek

is works. Then there is a ? quistionmark less.

Q:
How can I solve this??
I think the problem is here

<form action="index.phpid=77" method="GET">

thanx in advantage

#################################################################
<?php
echo "<form>
<fieldset id=fieldset1
style=postion:absolute
width:300
height:100
top:20
left:10
>";

echo "<legend>Zoek Numatic distributeurs in uw omgeving</legend>";
echo "Vul de eerste 2 cijfers van uw postcode in</br>";
?>
</form>

<form action="index.phpid=77" method="GET">

<input type=text name=postcode size=2 maxlength=2>
<input type=submit name=submit value=zoek>
<form>
#################################################################