form not updating values

[djanim8]

I have a form with a combo box that when you click it, it should sumit the value selected..

here is the form code with asp code:
<form action="placeorder.asp" method="post" enctype="multipart/form-data" name="frmTypeCheck" id="frmTypeCheck">
Type of Check:
<label>
<select name="typeCheck" id="typeCheck" onChange="frmTypeCheck.submit();">
<%
if Session("CheckType")="" then
Response.write("<option selected value=" & Chr(34) & Chr(34) & ">-- Select a Type --" & vbCrLf)
else
Response.write("<option value=" & Chr(34) & Chr(34) & ">-- Select a Type --" & vbCrLf)
end if

While Not rsTypes.EOF
if Session("CheckType")=rsTypes("type") then
Response.write("<option selected value=" & chr(34) & rsTypes("type") & Chr(34) & ">" & rsTypes("type") & vbCrLf)
else
Response.write("<option value=" & chr(34) & rsTypes("type") & Chr(34) & ">" & rsTypes("type") & vbCrLf)
end if
if rsTypes.eof=false then rsTypes.movenext
Wend
%>
</select>
</label>
</form>

when it loads in, it doesn't keep the value from the typeCheck combo box.

here is the code I use to check the form value:

<%
if Request.form("typeCheck")="" then
Session("CheckType")=""
else
Session("CheckType")=Request.form("typeCheck")
end if
%>

anyone know why it isn't getting the value?