An undandled exсeption of type  'System.ObjectDisposedExсeption' occurred in system.windows.forms.dll 
Additional information: Cannot access a disposed object named "startForm"

 'текст по комбобоксу 
 'Заполнение комбобокса по двигателям 
                Dim cmdEng As System.Data.SqlClient.SqlCommand = New System.Data.SqlClient.SqlCommand
                Dim daEng As System.Data.SqlClient.SqlDataAdapter = New System.Data.SqlClient.SqlDataAdapter(cmdEng)
                Dim dtsEng As DataSet = New AutoOtis.DataSetAutoOtis

                cmdEng.Connection = cn
                cmdEng.CommandType = CommandType.StoredProcedure
                cmdEng.CommandText = "UP_SelectCatEngin"
                cmdEng.Parameters.Add(New System.Data.SqlClient.SqlParameter("@IDModel", SqlDbType.Int,  4 ))
                cmdEng.Parameters( 0 ).Direction = ParameterDirection.Input
                cmdEng.Parameters( 0 ).Value = Me.ComboBox1.SelectedValue

                dtsEng.Tables.Add("UP_SelectCatEngin")
                daEng.Fill(dtsEng, "UP_SelectCatEngin")

                Me.cbxTypeEngine.DataSource = dtsEng.Tables("UP_SelectCatEngin")
                Me.cbxTypeEngine.ValueMember = "IDModel"
                Me.cbxTypeEngine.DisplayMember = "ModelEng"

 'текст долбаной startForm 

Public Class startForm
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public m_context As ApplicationContext

    Public Sub New(ByVal context As ApplicationContext)
        MyBase.New()

        Me.m_context = context
        Me.m_context.MainForm = Me
         'This call is required by the Windows Form Designer. 
        InitializeComponent()

         'Add any initialization after the InitializeComponent() call 

    End Sub

     'Form overrides dispose to clean up the component list. 
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)

    End Sub

     'Required by the Windows Form Designer 
    Private components As System.ComponentModel.IContainer

     'NOTE: The following procedure is required by the Windows Form Designer 
     'It can be modified using the Windows Form Designer.   
     'Do not modify it using the code editor. 
    Friend WithEvents ListBox1 As System.Windows.Forms.ListBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents SqlConnection1 As System.Data.SqlClient.SqlConnection
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Dim resources As System.Resources.ResourceManager = New System.Resources.ResourceManager(GetType(startForm))
        Me.ListBox1 = New System.Windows.Forms.ListBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.SqlConnection1 = New System.Data.SqlClient.SqlConnection
        Me.SuspendLayout()
         ' 
         'ListBox1 
         ' 
        Me.ListBox1.BackColor = System.Drawing.Color.LightSteelBlue
        Me.ListBox1.Font = New System.Drawing.Font("Papyrus",  14 . 25 !, CType((System.Drawing.FontStyle.Bold Or System.Drawing.FontStyle.Underline), System.Drawing.FontStyle), System.Drawing.GraphicsUnit.Point, CType( 0 , Byte))
        Me.ListBox1.ImeMode = System.Windows.Forms.ImeMode.NoControl
        Me.ListBox1.ItemHeight =  30 
        Me.ListBox1.Location = New System.Drawing.Point( 0 ,  0 )
        Me.ListBox1.Name = "ListBox1"
        Me.ListBox1.Size = New System.Drawing.Size( 122 ,  154 )
        Me.ListBox1.TabIndex =  2 
        Me.ListBox1.UseTabStops = False
         ' 

        Me.SqlConnection1.ConnectionString = "workstation id=""SPOSAD-LH2MILX6"";packet size=4096;integrated security=SSPI;data s" & _
            "ource=""sposad-LH2MILX6"";persist security info=False;initial catalog=OtisAuto"
         'Button1 
         ' 
        Me.Button1.BackColor = System.Drawing.SystemColors.InactiveCaption
        Me.Button1.ForeColor = System.Drawing.SystemColors.HotTrack
        Me.Button1.Location = New System.Drawing.Point( 513 ,  4 )
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size( 64 ,  25 )
        Me.Button1.TabIndex =  3 
        Me.Button1.Text = "Выбрать"
        Me.Button1.TextAlign = System.Drawing.ContentAlignment.MiddleLeft
         ' 
         'startForm 
         ' 
        Me.AutoScale = False
        Me.AutoScaleBaseSize = New System.Drawing.Size( 5 ,  13 )
        Me.BackgroundImage = CType(resources.GetObject("$this.BackgroundImage"), System.Drawing.Image)
        Me.ClientSize = New System.Drawing.Size( 608 ,  320 )
        Me.ControlBox = False
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.ListBox1)
        Me.Cursor = System.Windows.Forms.Cursors.Default
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None
        Me.MaximizeBox = False
        Me.MinimizeBox = False
        Me.Name = "startForm"
        Me.ShowInTaskbar = False
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "База ОТИС"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub startForm_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            Dim cm As System.Data.SqlClient.SqlCommand = New System.Data.SqlClient.SqlCommand
            cm.CommandType = CommandType.StoredProcedure
            cm.CommandText = "UP_AutenUser"   'ХП, определяющая роли (в данном случае - компании), в которых участвует текущий юзер 
            cm.Connection = Me.SqlConnection1

            Dim prGroup As SqlClient.SqlParameter = New SqlClient.SqlParameter
            prGroup.ParameterName = "@count"
            prGroup.SqlDbType = SqlDbType.Int
            prGroup.Direction = ParameterDirection.Output
            cm.Parameters.Add(prGroup)

            Dim IntCoun As String
            Dim myReader As SqlClient.SqlDataReader
            Me.SqlConnection1.Open()
            myReader = cm.ExecuteReader()
            Me.ListBox1.BeginUpdate()
            While myReader.Read()
                IntCoun = myReader.GetString( 0 )
                Me.ListBox1.Items.Add(IntCoun)
            End While
            Me.ListBox1.EndUpdate()
            myReader.Close()
            Me.SqlConnection1.Close()

        Catch exc As Exception
            MsgBox(exc.Message)
        End Try
    End Sub

    Dim Message As String
    Dim Caption As String = "ПОДТВЕРЖДЕНИЕ"
    Dim Buttons As Integer = MessageBoxButtons.YesNo
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim frm As BasicCover = New BasicCover
        Dim Result As DialogResult

        frm.strSQL = Me.SqlConnection1.ConnectionString
        frm.strGroupUser = Me.ListBox1.SelectedItem
        If frm.strGroupUser = "" Then
            MsgBox("Вы не выбрали компанию, с данными которой хотите работать. Выберите компанию и нажмите кнопку Выбрать")
            Exit Sub
        End If
        Me.m_context.MainForm = frm
        Message = "Вы выбрали работу с базой " & frm.strGroupUser & ". Подтвердите Ваш выбор, нажав ОК" & Chr( 13 ) & _
"Если хотите изменить выбор, то нажмите Нет"
        Result = MessageBox.Show(Me, Message, Caption, MessageBoxButtons.YesNo, _
        MessageBoxIcon.Question, MessageBoxDefaultButton.Button1, MessageBoxOptions.RightAlign)
         'frm.Label1.Text = frm.strGroupUser 
        If Result = DialogResult.Yes Then
            Close()
            frm.Show()
            frm.Activate()
            frm.Activate()
        End If

    End Sub
End Class

 uid  =  S a

dim cn as system.data.sqlclient.sqlconnection = new system.data.sqlclient.sqlconnection 

cn.ConnectionString=AutoOtis.BasicCover.strSQL