Declarations/Instamtiation in ASP.Net - where is the appropriate place??

Greetings!!

Having just resolved a query, I had a look at the code to see what I could learn from the exercise and realise that I am not clear on where to declare/instyantiate my objects. Below are two examples, marked CORRECT  & WRONG (as I understand them), together with a comment on execution.

WRONG:

    protected SqlConnection sqlConnectC;
    protected SqlCommand sqlCommandC;

    protected void Page_Load(object sender, EventArgs e)
    {
      if (!Page.IsPostBack)
      {
       
      }
    }

    protected void Button1_Click1(object sender, EventArgs e)
    {
        sqlConnectC = new SqlConnection(conString);
        sqlCommandC = new SqlCommand("countContracty", sqlConnectC);
        sqlCommandC.CommandType = CommandType.StoredProcedure;

        // Input parameter
        SqlParameter workParam = new SqlParameter("@startType", SqlDbType.Int);
        workParam.Direction = ParameterDirection.Input;
        workParam.Value = 99;
        sqlCommandC.Parameters.Add(workParam);

        // Output parameter
        SqlParameter workParam2 = new SqlParameter("@contractCount", SqlDbType.Int);
        workParam2.Direction = ParameterDirection.Output;
        sqlCommandC.Parameters.Add(workParam2);

        if (RadioButtonList1.SelectedIndex == 0)
        {
            sqlCommandC.Parameters["@startType"].Value = 0;
        }
        else
        {
            sqlCommandC.Parameters["@startType"].Value = 1;
        }

        sqlConnectC.Open();
        sqlCommandC.ExecuteNonQuery();
        sqlConnectC.Close();

         lblCount.Text = "Count: " +sqlCommandC.Parameters[1].Value.ToString();

Execution: App runs 100%!!!


CORRECT:

    protected SqlConnection sqlConnectC;
    protected SqlCommand sqlCommandC;

    protected void Page_Load(object sender, EventArgs e)
    {
      if (!Page.IsPostBack)
      {
          sqlConnectC = new SqlConnection(conString);
          sqlCommandC = new SqlCommand("countContracty", sqlConnectC);
          sqlCommandC.CommandType = CommandType.StoredProcedure;

          // Input parameter
          SqlParameter workParam = new SqlParameter("@startType", SqlDbType.Int);
          workParam.Direction = ParameterDirection.Input;
          workParam.Value = 99;
          sqlCommandC.Parameters.Add(workParam);

          // Output parameter
          SqlParameter workParam2 = new SqlParameter("@contractCount", SqlDbType.Int);
          workParam2.Direction = ParameterDirection.Output;
          sqlCommandC.Parameters.Add(workParam2);
       
      }
    }

    protected void Button1_Click1(object sender, EventArgs e)
    {

        if (RadioButtonList1.SelectedIndex == 0)
        {
            sqlCommandC.Parameters["@startType"].Value = 0;
        }
        else
        {
            sqlCommandC.Parameters["@startType"].Value = 1;
        }

        sqlConnectC.Open();
        sqlCommandC.ExecuteNonQuery();
        sqlConnectC.Close();

Execution:  

Server Error in '/Stored_Proc_03_Scalar_Param' Application.
Object reference not set to an instance of an object.
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.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 44:         if (RadioButtonList1.SelectedIndex == 0)
Line 45:         {
Line 46:             sqlCommandC.Parameters["@startType"].Value = 0;
Line 47:         }
Line 48:         else

Source File: d:\MyStuff - Allan\New Horizons\Training\Course_Practicals\ASP_Projects\Stored_Proc_03_Scalar_Param\Default.aspx.cs    Line: 46