SqlCommand error: "Object reference not set to an instance of an object."

i set the drop down list value in page load .i ll change the value of it and once i click button the value must be displayed.but error is popped out in drop down list in button click event

public partial class edit : System.Web.UI.Page
{
   
    protected void Page_Load(object sender, EventArgs e)
    {
        string degree1; string id1;

        ArrayList AlDay = new ArrayList(); AlDay.Add("SELECT THE GENDER");

        AlDay.Add("F"); AlDay.Add("M");
        DropDownList1.DataSource = AlDay;
        
    
      

            id1 = "";
            degree1 = Request.QueryString["degree"];
            id1 = Request.QueryString["name"];

            if (!IsPostBack)
        &n

I have the following code

Dim ls_case_no() As String = Nothing
 Dim li_case_count As Integer = 0

  Dim li_case As String = ""
         li_case = xmlLocNode.InnerText
                                            If Not li_case = "" Then
                                                'li_case = li_case.Replace("-", "")
                                                ls_case_id = li_case


                                                ReDim Preserve ls_case_no(li_case_count)
                                                li_case_count = li_case_count + 1
                                                ls_case_no(li_case_count - 1) = ls_case_id
                                            End If

 myNode = xmlLocNode.SelectSingleNode("nc:CaseTrackingID", nsMgr)
                                             If Not myNode.InnerText = "" Then
                                                Dim li_case As String = myNode.InnerText
                                               lbl_caseno.Text = li_case
                                                ls_case_core = li_case
                                            End If

 If Not ls_case_no.Length = 0 Then
            For d = 0 To ls_case_no.Length - 1
                If Not ls_case_no(d) = ls_case_core Then
                     lb

Hi,

I'm getting the following error from Visual studio 2008 each time i debug my C# application: