function getXmlHttp()
{
    var xmlhttp;
    try 
    {
        xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) 
    {
        try 
        {
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (E) 
        {
            xmlhttp = false;
        }
    }
    if ( !xmlhttp && typeof XMLHttpRequest != 'undefined' ) 
    {
        xmlhttp = new XMLHttpRequest();
    }
    return xmlhttp;
}

function get_options_tags(params, target_obj)
{
    var xmlhttp = getXmlHttp();
    xmlhttp.open('POST', 'filter_processor', true);
    xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xmlhttp.onreadystatechange = function() 
    {
        if (xmlhttp.readyState == 4) 
        {
            if(xmlhttp.status == 200) 
            {
                target_obj.innerHTML = xmlhttp.responseText;
            }
        }
    };
    xmlhttp.send(params);
}

function replace_selects()
{
    var selects_namespace = new Array('category', 'vendor', 'good');
    var params = '';
    for ( i=0; i<3; i++ )
    {
        var select_obj = document.getElementById(selects_namespace[i]);
        var id_value = select_obj.options[select_obj.selectedIndex].value;
        params += selects_namespace[i] + '=' + id_value + '&';
    }
//    alert(params);
    for ( i=0; i<3; i++ )
    {
        var td_obj = document.getElementById('select_'+selects_namespace[i]);
        get_options_tags( params + 'action=' + selects_namespace[i], td_obj );
    }
}