asp. net datalist can move up and down the implementation example after binding the data

 
if (e.CommandName == "Up") 
{ 
int index = e.Item.ItemIndex; 
string TitleID = rgZdgz.MasterTableView.DataKeyValues[index]["TitleID"].ToString().Trim(); 

if (e.Item.ItemIndex > 0) 
{ 
ZdgzTitles.ZdgzTitlesDisPlayNum(rgZdgz.MasterTableView.DataKeyValues[index]["TitleID"].ToString().Trim(), 
rgZdgz.MasterTableView.DataKeyValues[index-1]["TitleID"].ToString().Trim()); 
Clear(); 
rgZdgz.Rebind(); 
} 
else 
{ 
ShowMessage(" This item is at the top and cannot be moved up. "); 
} 
} 
else if (e.CommandName == "Down") 
{ 
int index = e.Item.ItemIndex; 
string TitleID = rgZdgz.MasterTableView.DataKeyValues[index]["TitleID"].ToString().Trim(); 

if (e.Item.ItemIndex < rgZdgz.Items.Count - 1) 
{ 
ZdgzTitles.ZdgzTitlesDisPlayNum(rgZdgz.MasterTableView.DataKeyValues[index]["TitleID"].ToString().Trim(), 
rgZdgz.MasterTableView.DataKeyValues[index+1]["TitleID"].ToString().Trim()); 
Clear(); 
rgZdgz.Rebind(); 
} 
else 
{ 
ShowMessage(" This item is at the bottom and cannot be moved down. "); 
}