function check_input(which)
        {
        if (which == 2)
            {
            if (document.SEARCHFORM.f_property_id.value == 'Objekt ID' || document.SEARCHFORM.f_property_id.value == 'Property ID' || document.SEARCHFORM.f_property_id.value == 'Referencia ID')
                {document.SEARCHFORM.f_property_id.value = '';};
            }
        else
            {
            if (document.SearchforID.f_property_id.value == 'Objekt ID' || document.SearchforID.f_property_id.value == 'Property ID' || document.SearchforID.f_property_id.value == 'Referencia ID')
                {document.SearchforID.f_property_id.value = '';};
            };
        }