Help needed sending a simple form... but in a new resizable window!!!

[neilbradford]

I need to submit form data the simple way but including a userID as going to a shopping cart gateway, and to a specific server (all info in the code below) but want the new window to open at a particular size.
I've tried the code below but just opens a new window with the right data sent but NOT at size specified! The code below contains the server name, userid, and product plus options.
What am I doing wrong??? Please help...!!!

<form action="http://ww10.aitsafe.com/cf/addmulti.cfm" name="userid" method="post" target="code">
<input type="Hidden" name="userid" value="C9300656">
<INPUT TYPE="HIDDEN" NAME="product1" VALUE="Cocktail Ring : Ref R2070">
<input type="Hidden" name="price1" value="9.99">
<input type=text name="qty1" value="1" size="2" MAXLENGTH="2">
<SELECT NAME="product1" SIZE="1">
<OPTION VALUE="Cocktail Ring R2070 Size J">J</OPTION>
<OPTION VALUE="Cocktail Ring R2070 Size L">L</OPTION>
<OPTION VALUE="Cocktail Ring R2070 Size P">P</OPTION></SELECT>
<input type="submit" value="submit" onclick="
NewWindow('','code',650,500,'resizable,scrollbars',
'center');document.forms.userid.submit();return false;" />
</form>