I am trying to fill a combo box using an array. I have tried filling the combo box using a dataset and I keep getting the same error.

This is my error:

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 88: Do While dr.Read
Line 89: stAl.Add("CATEGORY_DESC")
Line 90: cbcategory_id.Items.Add("CATEGORY_DESC")
Line 91: Loop
Line 92:


Source File: c:\inetpub\wwwroot\WebApplication2\Default.aspx.vb Line: 90

Stack Trace:


[NullReferenceException: Object reference not set to an instance of an object.]
   WebApplication2.WebForm4.LoadDataSet() in c:\inetpub\wwwroot\WebApplication2\Default.aspx.vb :90
   WebApplication2.WebForm4.Page_Load(Object sender, EventArgs e) in c:\inetpub\wwwroot\WebApplication2\Default.aspx.vb :58
   System.Web.UI.Control.OnLoad(EventArgs e)
   System.Web.UI.Control.LoadRecursive()
   System.Web.UI.Page.ProcessRequestMain()


This is my Code:


    Private Sub LoadDataSet()
        Dim dr As OleDbDataReader
        Dim strQry As String
        Dim stAl As New ArrayList

        sqlComm = New OleDbCommand(strQry, DbConn)

        strQry = "SELECT CATEGORY_ID, CATEGORY_DESC FROM INCIDENT.CATEGORIES"
        DbConn.Open()

        sqlComm.CommandText = strQry
        dr = sqlComm.ExecuteReader()

        If dr.HasRows Then
            Do While dr.Read
                stAl.Add("CATEGORY_DESC")
                cbcategory_id.Items.Add("CATEGORY_DESC")
            Loop

        End If
        dr.Close()
        DbConn.Close()
    End Sub

Please help me as soon as possible.

Thanks in advance.

Trena