Need Help With ConfigurationSettings.AppSettings And Inserting Data

I have a function built into a button that I would like to take the values in textboxes and add them to a new record in a ms sql server database. I am having trouble because I am not sure if I am calling the connection string, which is in the web.config file correctly.
Here is what I have:

    private void Button1_Click(object sender, System.EventArgs e)
    {
        lblErrMsg.Text = "";
        lblRecsAff.Text = "";
        //string strGary;
        string strGary = ConfigurationSettings.AppSettings["MyConnectionString"].ToString();
        SqlConnection conn = new SqlConnection(strGary);
        //string strSQL = "INSERT INTO tbl_Jobs (JobName,JobDescription,JobLocation,JobRequirements,JobActive) VALUES (@JobName,@JobDescription,@JobLocation,@JobRequirements,@JobActive)";
        string strSQL = "INSERT INTO aspnet_Expenses (ExpenseCreated,ExpenseUserId,ExpenseDate,RentalCar,AirTravel,PersonalCar,Hotel,PerDiem,Misc,MealBreakfast,MealLunch,MealDinner,Entertainment,ExpenseDescription,ExpenseCreatorUserId) VALUES (@ExpenseCreated,@ExpenseUserId,@ExpenseDate,@RentalCar,@AirTravel,@PersonalCar,@Hotel,@PerDiem,@Misc,@MealBreakfast,@MealLunch,@MealDinner,@Entertainment,@ExpenseDescription,@ExpenseCreatorUserId)";

        SqlCommand cmd = new SqlCommand(strSQL, conn);

        cmd.Parameters.Add(new SqlParameter("@ExpenseEntryCreatorUserName", SqlDbType.NText, 255)).Value =  "genericUserName";
        cmd.Parameters.Add(new SqlParameter("@AirTravel", SqlDbType.Decimal, 0)).Value =  AirTravel.Text;
        cmd.Parameters.Add(new SqlParameter("@RentalCar", SqlDbType.Decimal, 0)).Value =  RentalCar.Text;
        cmd.Parameters.Add(new SqlParameter("@PersonalCar", SqlDbType.Decimal, 0)).Value =  PersonalCar.Text;
        cmd.Parameters.Add(new SqlParameter("@Hotel", SqlDbType.Decimal, 0)).Value =  Hotel.Text;
        cmd.Parameters.Add(new SqlParameter("@PerDiem", SqlDbType.Decimal, 0)).Value =  PerDiem.Text;
        cmd.Parameters.Add(new SqlParameter("@Misc", SqlDbType.Decimal, 0)).Value =  Misc.Text;
        cmd.Parameters.Add(new SqlParameter("@MealBreakfast", SqlDbType.Decimal, 0)).Value =  MealBreakfast.Text;
        cmd.Parameters.Add(new SqlParameter("@MealLunch", SqlDbType.Decimal, 0)).Value =  MealLunch.Text;
        cmd.Parameters.Add(new SqlParameter("@MealDinner", SqlDbType.Decimal, 0)).Value =  MealDinner.Text;
        cmd.Parameters.Add(new SqlParameter("@Entertainment", SqlDbType.Decimal, 0)).Value =  Entertainment.Text;
        cmd.Parameters.Add(new SqlParameter("@ExpenseDate", SqlDbType.DateTime, 0)).Value =  ExpenseDate.Text;
        cmd.Parameters.Add(new SqlParameter("@ExpenseDescription", SqlDbType.NText, 1000)).Value = ExpenseDescription.Text;
        //cmd.Parameters.Add(new SqlParameter("@ExpenseEntryUserName", SqlDbType.NText, 255).Value =  ExpenseEntryUserName.Text;
        //end added by vf

        //cmd.Parameters.Add(new SqlParameter("@JobName", SqlDbType.WChar, 255)).Value = TextBox1.Text;
        //cmd.Parameters.Add(new SqlParameter("@JobDescription", SqlDbType.LongVarChar, 1500)).Value = TextBox2.Text;
        //cmd.Parameters.Add(new SqlParameter("@JobLocation", SqlDbType.WChar, 255)).Value = TextBox3.Text;
        //cmd.Parameters.Add(new SqlParameter("@JobRequirements", SqlDbType.WChar, 255)).Value = TextBox6.Text;
        //cmd.Parameters.Add(new SqlParameter("@Actice", SqlDbType.Boolean, 1)).Value = CheckBox1.Checked;

        DateTime strToday = DateTime.Today;
        ExpenseDate.Text = Convert.ToString("tstrToday");

        int intRowsAff;
        try
        {
            cmd.Connection.Open();
            intRowsAff = cmd.ExecuteNonQuery();
            cmd.Connection.Close();
        }
        catch (Exception ex)
        {
            lblErrMsg.Text = ex.Message;
        }
        //lblRecsAff.Text = intRowsAff + " record(s) inserted using " & strSQL;
        //lblRecsAff.Text = intRowsAff + " record(s) were added to the expense report.";
    }

 
 
Any help would be greatly appreciated!