private void btnRemoveTile_Click(object sender, EventArgs e)
        {     //If there's a tile set selected.
            if (cboTiles.SelectedIndex >= 0)
            { //Put the current index in a buffer.
                int Index = cboTiles.SelectedIndex;

                Helper.RemoveTileset(Index);
                //Move the current tile set.
                cboTiles.Items.RemoveAt(Index);
                TerrainAttribute.ListTileset.RemoveAt(Index);

                //Replace the index with a new one.
                if (cboTiles.Items.Count > 0)
                {
                    if (Index >= cboTiles.Items.Count)
                    {
                        cboTiles.SelectedIndex = cboTiles.Items.Count - 1;
                    }
                    else
                    {
                        cboTiles.SelectedIndex = Index;
                    }
                }
                else
                {
                    cboTiles.Text = "";
                }
            }
        }