error ขึ้นแบบนี้ The conversion of a nvarchar data type to a datetime data type resulted in an out-of-range value พอมีวิธีแก้หรือป่าวครับ

protected void btnSave_Click(object sender, EventArgs e)
    {
       
        string str = null;
        DataTable dt2 = null;
        string strOrderID = "0";
        int i = 0;
     
        connect_db();

        str = "insert into Orders (Order_Date,Cus_ID,Order_Name,Order_Address,Order_Tel,Order_PriceAll) " + " VALUES " + " (@sOrderDate,@sid,@sName,@sAddress,@sTel,@sss)";
        SqlCommand insert = new SqlCommand(str, dbcon.conn);
        insert.Parameters.AddWithValue("@sOrderDate", DateTime.Now.ToString());
         insert.Parameters.AddWithValue("@sid", txtid.Text);
        insert.Parameters.AddWithValue("@sName", txtName.Text);
        insert.Parameters.AddWithValue("@sAddress", txtAddress.Text);
        insert.Parameters.AddWithValue("@sTel", txtTel.Text);
        insert.Parameters.AddWithValue("@sss", lblSumTotal.Text);
        insert.ExecuteNonQuery();


        str = "SELECT Max(Order_ID) As sOrderID FROM Orders ";
        SqlDataAdapter da = new SqlDataAdapter(str, dbcon.conn);
        DataTable dt1 = new DataTable();
        da.Fill(dt1);
        if (dt1.Rows.Count > 0)
        {
            strOrderID = dt1.Rows[0]["sOrderID"].ToString();
        }
        dt2 = (DataTable)Session["myCart"];
        for (i = 0; i <= dt2.Rows.Count - 1; i++)
        { /*
            str = "INSERT INTO OrderDetail (Order_ID,Pro_ID,ODt_Amount) " + " VALUES " + " ('" + strOrderID + "','" + dt2.Rows[i]["Pro_ID"] + "','" + dt2.Rows[i]["ODt_Amount"] + "')";
            var _with1 = insert;
            _with1.CommandText = str;
            _with1.CommandType = CommandType.Text;
           * ใช้ชุดคำสั่ง sql ที่เก็บอยู่ในตัวแปร str
            _with1.ExecuteNonQuery();

           */


            str = "INSERT INTO OrderDetail (Order_ID,Pro_ID,ODt_Amount,ODt_Price) " + " VALUES " + " ('" + strOrderID + "','" + dt2.Rows[i]["Pro_ID"] + "','" + dt2.Rows[i]["ODt_Amount"] + "','" + strTotal+ "')";
            var _with1 = insert;
            _with1.CommandText = str;
            _with1.CommandType = CommandType.Text;
            _with1.ExecuteNonQuery();
            
           
        }
        SqlCommand cmd = new SqlCommand("update [Orders] set Order_Status='please payment' where Order_ID=" + strOrderID + "", dbcon.conn);

            
            cmd.ExecuteNonQuery();
        dbcon.closeDB();

        Session.Remove("myCart");
        Response.Redirect("Vieworder.aspx?Order_ID=" + strOrderID);

       
        }