help! insert into mdb database using datatable

[CloudDust]

hi,

i'm having a problem with this set of codes.
i'm trying to insert data into datatable and update it into a database but everytime i click the save button

an OledbException will occur

Private myConnect As OleDbConnection
    Private myDataadapter As OleDbDataAdapter
    Private myDataTable As DataTable
    Private cmbInsert As OleDbCommand    
 
    Private Sub FormItemType_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim dbConnect As String = "Provider=Microsoft.JET.OLEDB.4.0;data source=D:\prodType.mdb"
 
        myConnect = New OleDbConnection(dbConnect)
        Dim mySqlQuery As String = "Select *from ProductTypeInfo"
        myDataTable = New DataTable
        myDataadapter = New OleDbDataAdapter(mySqlQuery, dbConnect)
        cmbInsert = New OleDbCommand
        cmbInsert.CommandText = "Insert into ProductTypeInfo (ProductTypeID, ProductTypeName) values (@ProductTypeID, @ProductTypeName)"
        cmbInsert.Connection = myConnect
        cmbInsert.Parameters.Add(New OleDbParameter("@ProductTypeID", OleDbType.BSTR))
        cmbInsert.Parameters.Add(New OleDbParameter("@ProductTypeName", OleDbType.BSTR))
        myDataadapter.InsertCommand = cmbInsert
 
        myConnect.Open()
        myDataadapter.Fill(myDataTable)
        myConnect.Close()
        DataGrid1.DataSource = myDataTable
 
    End Sub
 
    Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
        myConnect.Open()
        myDataadapter.Update(myDataTable)
 
        myConnect.Close()
    End Sub