This is a program to open an pdf file.. and to check the spelling mistakes and grammer mistakes

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim proc As New Process()
        With proc.StartInfo
            .Arguments = " Acrobe Reader"
            .UseShellExecute = True
            .WindowStyle = ProcessWindowStyle.Maximized
            .WorkingDirectory = "C:\Program Files\Adobe\Reader 9.0\Reader\" '<----- Set Acrobat Install Path
            .FileName = "AcroRd32.exe" '<----- Set Acrobat Exe Name
        End With
        proc.Start()
        proc.Close()
        proc.Dispose()
    End Sub
    Private Sub SpellOrGrammarCheck(ByVal blnSpellOnly As Boolean)
        Try
            Dim objWord As Object
            Dim objTempDoc As Object
            Dim iData As IDataObject
            If Textbox1.Text = "" Then
                Exit Sub
            End If
            objWord = New WordApplication1.Form1()
''Its getting error here
            objTempDoc = objWord.Documents.Add
            objWord.Visible = False
            objWord.WindowState = 0
            objWord.Top = -3000
            Clipboard.SetDataObject(Textbox1.Text)
            With objTempDoc
                .Content.Paste()
                .Activate()
                If blnSpellOnly Then
                    .CheckSpelling()
                Else
                    .CheckGrammar()
                End If
                .Content.Copy()
                iData = Clipboard.GetDataObject
                If iData.GetDataPresent(DataFormats.Text) Then
                    Textbox1.Text = CType(iData.GetData(DataFormats.Text), _
                        String)
                End If
                .Saved = True
                .Close()
            End With
            objWord.Quit()
            MessageBox.Show("The spelling check is complete.", _
                "Spell Checker", MessageBoxButtons.OK, _
                MessageBoxIcon.Information)
        Catch COMExcep As Runtime.InteropServices.COMException
            MessageBox.Show( _
                "Microsoft Word must be installed for Spell/Grammar Check " _
                & "to run.", "Spell Checker")
        Catch Excep As Exception
            MessageBox.Show("An error has occurred.", "Spell Checker")
        End Try
    End Sub
    Private Sub btnSpellCheck_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles btnSpellCheck.Click
        SpellOrGrammarCheck(True)
    End Sub
    Private Sub btnGrammarCheck_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles btnGrammarCheck.Click
        SpellOrGrammarCheck(False)
    End Sub
End Class