function setTrip()
{
    var qs = document.location.search.substring(1);
    var params = qs.split('&');
    for(var param in params)
    {
        var keyValue = params[param].split('=');
        if(keyValue[0] == 'country')
        {
            countryIndex = parseInt(keyValue[1],10);
        }
        else if(keyValue[0] == 'trip')
        {
            tripIndex = parseInt(keyValue[1],10);
        }
    }
    var form = document.forms[0];
    var countryDropDown = form.country;
    countryDropDown.selectedIndex = countryIndex+1;
    countryChanged(countryDropDown);
    form.trip.selectedIndex = tripIndex+1;
    tripChanged(form.trip);
}