close connection error

When you open the connection (ocon.Open), check the ocon.ConnectionState and open it only if the connection state is closed.

Generally this error occurs when connection is already opened and you are trying to open it again
so...
Place all your code in try block.
In Finally block write

ocon.close()

so that when exception occurs your connection will be close.

if the connection is already opened then such error will come.
do one thing to rectify that...
in 2 ways you can implement or rectify it

first way

if (ocon.State == ConnectionState.Open)
{
ocon.Close();
}
ocon.Open();

second way
if (ocon.State == ConnectionState.Close)
{
ocon.Open();
}

Dear sir,
when i execute the program there is one more record added in grid but not updated when i was clicking edit link button.
code:


private void Binddata()
{
string selectSQL = "SELECT * FROM reservation";
ocon.Open();
SqlCommand cmd = new SqlCommand(selectSQL, ocon);
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();

adapter.Fill(ds, "reservation");
ocon.Close();
gvreservation.DataSource = ds;
gvreservation.DataBind();
}

protected void gvreservation_RowCommand(object sender, GridViewCommandEventArgs e)
{
string id = ((TextBox)gvreservation.FooterRow.FindControl("txtFCustomerID")).Text;
string name = ((TextBox)gvreservation.FooterRow.FindControl("txtFCustomerName")).Text;
string age = ((TextBox)gvreservation.FooterRow.FindControl("txtFAge")).Text;
string location = ((DropDownList)gvreservation.FooterRow.FindControl("ddlFLocation")).Text;
string class1 = ((DropDownList)gvreservation.FooterRow.FindControl("ddlFClass")).Text;
ocon.Open();
string sqlstatement ="Insert into reservation(CustomerID,CustomerName,Age,Location,Class)values(@CustomerID,@CustomerName,@Age,@Location,@Class)";
SqlCommand cmd = new SqlCommand(sqlstatement,ocon);
cmd.Parameters.Add("@CustomerID",id);
cmd.Parameters.Add("@CustomerName",name);
cmd.Parameters.Add("@Age",age);
cmd.Parameters.Add("@Location",location);
cmd.Parameters.Add("@Class",class1);
cmd.ExecuteNonQuery();
ocon.Close();
Binddata();
}
protected void gvreservation_RowEditing(object sender, GridViewEditEventArgs e)
{
string id = ((TextBox)gvreservation.FooterRow.FindControl("txtFCustomerID")).Text;
string name = ((TextBox)gvreservation.FooterRow.FindControl("txtFCustomerName")).Text;
string age = ((TextBox)gvreservation.FooterRow.FindControl("txtFAge")).Text;
string location = ((DropDownList)gvreservation.FooterRow.FindControl("ddlFLocation")).Text;
string class1 = ((DropDownList)gvreservation.FooterRow.FindControl("ddlFClass")).Text;
string sqlstatements = "update reservation set CustomerName=@CustomerName,Age=@Age,Location=@Location,Class=@Class where CustomerID=@CustomerID";
ocon.Open();
SqlCommand cmd = new SqlCommand(sqlstatements,ocon);
cmd.Parameters.Add("@CustomerID",id);
cmd.Parameters.Add("@CustomerName",name);
cmd.Parameters.Add("@Age",age);
cmd.Parameters.Add("@Location",location);
cmd.Parameters.Add("@Class",class1);
cmd.ExecuteNonQuery();
ocon.Close();

}
protected void gvreservation_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
string id = ((TextBox)gvreservation.FooterRow.FindControl("txtFCustomerID")).Text;
string sqlstatement = "Delete from reservation where CustomerID=@CustomerID";
ocon.Open();
SqlCommand cmd = new SqlCommand(sqlstatement,ocon);
cmd.Parameters.Add("@CustomerID",id);
cmd.ExecuteNonQuery();
ocon.Close();
Binddata();
}
}