datagrid run time problem

السلام عليكم

لدى خطا دائما ما يتكرر مع استخدامى لل datagrid

لذا كنت ارجو ان يساعدنى احد حيث ان الخطا يقول

اقتباس

Specified argument was out of the range of valid values. Parameter name: index

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values. Parameter name: index

public void BindData()
  {
  	string myconn= "DRIVER={MySQL ODBC 3.51 Driver};" +
    "SERVER=localhost;" +
    "DATABASE=test;" +
    "UID=root;" +
    "PASSWORD=;" +
    "OPTION=3";
  	OdbcConnection Conn=new OdbcConnection(myconn);
  	OdbcCommand myCommand=new OdbcCommand("select UserID,UserName,F_Name,L_Name,Email from Users",Conn);
  	Conn.Open();
  	this.DataGrid1.DataSource=myCommand.ExecuteReader();
  	this.DataGrid1.DataBind();
  	Conn.Close();
  }

private void DataGrid1_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
  	this.DataGrid1.EditItemIndex=-1;

string un,fn,ln,em;
  	string uid;
  	TableCell cell1 = (TableCell)e.Item.Controls[1];
  	uid = (string)((TextBox)cell1.Controls[1]).Text;
  	TableCell tc2=(TableCell)e.Item.Controls[2];
    un=(string)((TextBox)tc2.Controls[1]).Text;
TableCell tc3=(TableCell)e.Item.Controls[3];
  	fn=((TextBox)tc3.Controls[1]).Text;
  	TableCell tc4=(TableCell)e.Item.Controls[4];
  	ln=((TextBox)tc4.Controls[1]).Text;
  	TableCell tc5=(TableCell)e.Item.Controls[5];
  	em=((TextBox)tc5.Controls[1]).Text;
  	string updatecomm="";
  	if(uid=="")//new one
  	{
    updatecomm+= "INSERT INTO";
    updatecomm += " Users VALUES ";
    updatecomm += "('"+un+"','"+fn+"','"+ln+"',"+em+")";
  	}
  	else//edit
  	{
  	
    updatecomm+="update Users set";
    updatecomm+="UserName='"+un+"',F_Name='"+fn+"',L_Name='"+ln+"' ,Email="+em+" ";

  	}
string myconn= "DRIVER={MySQL ODBC 3.51 Driver};" +
    "SERVER=localhost;" +
    "DATABASE=test;" +
    "UID=root;" +
    "PASSWORD=;" +
    "OPTION=3";
  	OdbcConnection Conn=new OdbcConnection(myconn);
  	OdbcCommand Command=new OdbcCommand(updatecomm,Conn);

Conn.Open();
  	Command.ExecuteNonQuery();
  	Conn.Close();
  
  	BindData();

الخطا فى هذا السطر

uid = (string)((TextBox)cell1.Controls[1]).Text;

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