How automatically filter products on a page based on dropdown selection?

I have added a select box to the top of a working page - the working page shows Products which belong to a Department passed via. URL

The select box I have added - shows printers in the dropdown which belong to the Department Name.
What I would like to do now is filter the products based on the selected item in the drop down.

I have a table called [1digiPrinter] - which displays the PrinterID, Manufacturer and PrinterName
and
a table called [1digiPrinterProduct] which has PrinterID and ProductID so that they can be mapped.

So in essence the filter needs to say - show me all Products where the ProductID = [1digiPrinterProduct].ProductID and PrinterID = [1digiPrinterProduct].PrinterID (although I know at this stage, I'm not passing the PrinterID out of the select, only the PrinterName

Basically - how would I filter the products like this but more importantly - how can I action this filter everytime someone selects a different printer?  (Resubmit to same page - ideally automatically without having to click the submit button)

Note - there are two seperate forms on this page.  The other form does a comparison of 2 or more products.

If you need any more info - give me a shout.

I hope you can help.

Thanks in advance!

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<%
 
If PrinterName = "" Then

  Dim MyConn, RS, connStr
 
 
  Response.Write "Selection = <b>" & PrinterName & "</b><br>"
 
  Set MyConn=Server.CreateObject("ADODB.Connection")
  connStr=""

  SQL = "Select Distinct PrinterName From [1digiPrinter] Where Manufacturer = '"&rs1digiDepartment("DepartmentName")&"'"
  MyConn.Open connStr
  Set RS = MyConn.Execute(SQL)
%>




   
        
  <p>

  <form method = "Post">
    <select name="PrinterName">


      <option selected>--Select PrinterName--

      <%While Not RS.EOF%>

      <option value="<%=RS("PrinterName")%>">

      <%=RS.Fields("PrinterName")%>

      <%
    RS.MoveNext
  Wend

  RS.Close
  MyConn.Close
  Set RS = Nothing
  Set MyConn = Nothing
 
 
%>

    </select>

<input type="submit" name="save" value="Show me Ink Cartridges for this printer">
  </p>
  <p>
 
    <input type="hidden" name="PrinterName" size="20" value="<%=PrinterName%>">
  </p>
  </form>


<%End If%>


      <!--  Display the description -->
      &nbsp;&nbsp;<img src="/images/compare.gif" alt="Click two or more checked boxes and then click on Compare at the bottom to compare products" width="200" height="95">
      <%

'  Create an ADO database connection
set db1digiProduct = server.createobject("adodb.connection")

'  Create the record set
set rs1digiProduct = server.CreateObject("adodb.recordset")

'  Open the connection using our ODBC file DSN
db1digiProduct.open ""

'  Build the sql statement to retrieve the products in
'  the department.  The ID of the department is passed in.
sql = "execute [1digi_RetrieveDeptProducts] " & request("DepartmentID")

'  Execute the SQL statement and retrieve the record set
set rs1digiProduct = db1digiProduct.Execute(sql)

'  We are going to rotate the images from left
'  to right.
%>
      &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
      <form action="compare.asp" method="post" target="_blank">
        <table width="100%" height="129" border="0">
          <tr>
            <%
Flag=0

'  Loop through the products record set
do until rs1digiProduct.EOF

'  Retrieve the product information to be displayed.
ProductName = rs1digiProduct("ProductName")
ProductImage = rs1digiProduct("ProductImage")
ProductID = rs1digiProduct("ProductID")
ProductPriceexcvat = rs1digiProduct("ProductPriceexcvat")
ProductPriceIncVAT = rs1digiProduct("ProductPriceIncVAT")


'  rotate the
'  product images from left to right.


if Flag = 1 Then

Flag=1
%>
            <!-- Build the link to the product information.  -->
         
            </tr><tr>
            <td width="100%" height="110" align="left" valign="top">
              <div align="left">
                <p align="left"> <strong><%=ProductName%></strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong><%=formatcurrency(ProductPriceExcVAT)%>ex. VAT&nbsp;&nbsp;<%=formatcurrency(ProductPriceIncVAT)%> inc. VAT</strong> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                </p>
                <p align="center"><a href="product.asp?ProductID=<%=ProductID%>">
                  </a> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="product.asp?ProductID=<%=ProductID%>"><img src="images/products/<%=ProductImage%>" border="0" align="middle"></a>&nbsp;
                  <a href="additem.asp?ProductID=<%=ProductID%>&Quantity=1&ProductName=<%=ProductName%>&Productpriceincvat=<%=ProductPriceincvat%>&ProductShipping1stClass=<%=rs1digiProduct("ProductShipping1stClass")%>&ProductShipping2ndClass=<%=rs1digiProduct("ProductShipping2ndClass")%>&ProductShipping1stClassR=<%=rs1digiProduct("ProductShipping1stClassR")%>&ProductShippingSD=<%=rs1digiProduct("ProductShippingSD")%>"><img src="/images/addtobasket.gif" alt="Add to basket" width="100" height="24" border="0" align="right"></a>
                </p>
                <a href="product.asp?ProductID=<%=ProductID%>"></a>
                  &nbsp;&nbsp;&nbsp;&nbsp; <input type="checkbox" name="ProductID" value="<%=ProductID%>">
                Compare <hr></div>
              </td>
          <% else %>
          <!-- Build the link to the product information.  -->
            <td width="100%" height="110" align="left" valign="top">
              <div align="left">
                <p align="left"> <strong><%=ProductName%></strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong><%=formatcurrency(ProductPriceExcVAT)%>ex. VAT&nbsp;&nbsp;<%=formatcurrency(ProductPriceIncVAT)%> inc. VAT</strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                </p>
                <p align="center"><a href="product.asp?ProductID=<%=ProductID%>">
                  </a> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="product.asp?ProductID=<%=ProductID%>"><img src="images/products/<%=ProductImage%>" border="0" align="middle"></a>&nbsp;
                  <a href="additem.asp?ProductID=<%=ProductID%>&Quantity=1&ProductName=<%=ProductName%>&Productpriceincvat=<%=ProductPriceincvat%>&ProductShipping1stClass=<%=rs1digiProduct("ProductShipping1stClass")%>&ProductShipping2ndClass=<%=rs1digiProduct("ProductShipping2ndClass")%>&ProductShipping1stClassR=<%=rs1digiProduct("ProductShipping1stClassR")%>&ProductShippingSD=<%=rs1digiProduct("ProductShippingSD")%>"><img src="/images/addtobasket.gif" alt="Add to basket" width="100" height="24" border="0" align="right"></a>
                </p>
                <a href="product.asp?ProductID=<%=ProductID%>"></a>
                  &nbsp;&nbsp;&nbsp;&nbsp; <input type="checkbox" name="ProductID" value="<%=ProductID%>">
                Compare
                <hr>
              </div>
              </td>
          <%

Flag=Flag+1




end if

'  Move to the next row
rs1digiProduct.movenext

loop

%>
         
        </tr></table>
        <p>
         
        </p><input type="submit" value="Compare">
      </form>
      <a href="product.asp?ProductID=<%=ProductID%>">
        </a>

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