protected void btnColumnField_Click(object sender, EventArgs e)
{
if (lbxFields.SelectedItem != null)
{
ListItem item = new ListItem(lbxFields.SelectedItem.Text, lbxFields.SelectedItem.Value);
// Removes from row fields and column fields
lbxRowFields.Items.Remove(item);
lbxColumnFields.Items.Remove(item);
// Adds to the end of column fields
lbxColumnFields.Items.Add(item);
}
}