/// <summary>
    /// Fills the given drop-down list with the available relationship types.
    /// </summary>
    private void DisplayAvailableRelationships()
    {
        if (drpRelationship.Items.Count == 0)
        {
            // Get the relationships from DB
            DataSet ds = RelationshipNameInfoProvider.GetAllRelationshipNames(CMSContext.CurrentSite.SiteID, "RelationshipAllowedObjects LIKE '%;##OBJECTS##;%'");
            if (!DataHelper.DataSourceIsEmpty(ds))
            {
                foreach (DataRow dr in ds.Tables[0].Rows)
                {
                    drpRelationship.Items.Add(new ListItem(dr["RelationshipDisplayName"].ToString(), dr["RelationshipNameID"].ToString()));
                }

                drpRelationship.Enabled = true;
            }
            else
            {
                drpRelationship.Items.Add(new ListItem(GetString("General.NoneAvailable"), ""));
                drpRelationship.Enabled = false;
            }
        }
    }