yo utilizo este desde un BD
Código PHP:
<script language = "JavaScript">
<%Dim x, count, y
SQL = "SELECT IdModelo, NombreModelo, IdMarca FROM Modelos"
CrearRs(objRS)
x=0
%>
// FUNCION DE COMBO BOX COMBINADO
function sublist(inform, selecteditem)
{
inform.subcatagory.length = 0
<%
count= 0
y=0
Do While Not rs.EOF
%>
x = <%= trim(y) %>;
subcat = new Array();
subcatagorys = "> <%=(rs("NombreModelo"))%>";
subcatagoryof = "<%=(rs("IdMarca"))%>";
subcatagoryid = "<%=(rs("IdModelo"))%>";
subcat[x,0] = subcatagorys;
subcat[x,1] = subcatagoryof;
subcat[x,2] = subcatagoryid;
if (subcat[x,1] == selecteditem) {
var option<%= trim(count) %> = new Option(subcat[x,0], subcat[x,2]);
inform.subcatagory.options[inform.subcatagory.length]=option<%= trim(count)%>;
}
<%
count = count + 1
y = y + 1
rs.MoveNext
Loop
rs.Close()
Set rs = Nothing
%>
}
</script>
Código PHP:
<select size="1" id="cat" name="MarcaVehiculo" onChange = "javascript:sublist(this.form, cat.value);">
<option selected value="0">Seleccione</option>
<%
SQL = "SELECT IdMarca, NombreMarca FROM Marcas"
CrearRS(objRS)
Do While Not rs.EOF%>
<option value="<%=rs("IdMarca")%>">* <%=rs("NombreMarca")%></option>
<%rs.MoveNext
Loop
rs.Close()
Set rs = Nothing
%>
</select> [
<a href="javascript:;" onclick="FP_openNewWindow('250', '150', false, false, false, false, false, false, 'Vehiculo', /*href*/'agregar.asp?accion=marca')">
Agregar</a> ]</td>
</tr>
<tr>
<td width="30%" height="25" class="text" align="right">
<font color="#FF0000">*</font> Modelo::</td>
<td height="25" class="text" width="488" colspan="3">
<select id="subcatagory" name="ModeloVehiculo" size="1">
<option value="0">--------------------</option>
</select>