here i have written the code:

main page
<%@ Language=VBScript %>
<%
set con=server.CreateObject("adodb.connection")
set rs=server.CreateObject("adodb.recordset")
con.Open "super"
user_id=session("loginid")
rs.Open "select * from products order by itemno",con
%>
<%
while not rs.EOF
%>
<tr>
<td width="23%" style="border: 1 solid #C0C0C0" height="25" bgcolor="#BBCCED"><font face="Verdana" size="2"><%=rs(1)%></font></td>
<td width="23%" style="border: 1 solid #C0C0C0" height="25" bgcolor="#BBCCED"><font face="Verdana" size="2"><%=rs(2)%></font></td>
<td width="28%" style="border: 1 solid #C0C0C0" height="25" bgcolor="#BBCCED"><font face="Verdana" size="2"><%=rs(3)%></font></td>
<td width="6%" style="border: 1 solid #C0C0C0" height="25" bgcolor="#BBCCED">
<p align="center">
<select size="1" name="q">
<option selected value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
</select></td>


<td width="12%" style="border: 1 solid #C0C0C0" height="25" bgcolor="#BBCCED"><font face="Verdana" size="2">Rs.<%=rs(4)%></font></td>
<td width="8%" style="border: 1 solid #C0C0C0" height="25" bgcolor="#BBCCED">
<p align="center"><font face="Verdana" size="2"><input type="checkbox" name="checkbox1" value=<%=rs(0)%>></font></td>
</tr>

<%
rs.MoveNext
wend
end if
rs.Close
set rs = nothing
%>

***the second file
<%Response.Buffer=true %>
<%
item_id=Request.Form("checkbox1")

set con=server.CreateObject("adodb.connection")
set rs=server.CreateObject("adodb.recordset")
con.Open "super"

user_id=session("loginid")
itemid=split(item_id,",")
%>

<%

for i= lbound(itemid) to ubound(itemid)
%>
i value = <%=i%>
<%
quantity=Request.Form("q")
q=cint(i)+1

if QtyArray<>"" then
QtyArray=QtyArray&","&quantity
else
QtyArray=quantity
end if
rs.Open "select productname,unitprice from products where itemno=" & itemid(i),con

%>
<tr><td><%=rs(0) %>&nbsp;</td>
<td><%=rs(1)%>&nbsp;</td>
<TD><%=qtyArray%>&nbsp;</TD>
<td>
<%
total=rs(1)*(quantity)
grandtotal=grandtotal+total
Response.Write total
%> &nbsp;</td></tr>
<%

rs.close()
next
set rs=nothing

con.Close()
set con=nothing
%>