the ExecuteNonQuery problem()??pls help!!

i am doing a asp-database programming and i am having the following problem:
when i execute the following code, error appears and the stack trace as the following:

*****code*****
Sub Click_Grid(ByVal Sender as Object, ByVal E as DataGridCommandEventArgs)
If E.CommandSource.CommandName = "Edit" Then
Response.Redirect("./edit.aspx?EmployeeID=" _ & E.Item.Cell(1).Text)
ElseIf E.CommandSource.CommandName = "Delete" Then
Dim DBConn as OleDbConnection
Dim DBDelete As New OleDbCommand
Dim DBCommand As OleDbDataAdapter
Dim DSPageData as New DataSet
DBConn = New OleDbConnection("PROVIDER=" _  &"Microsoft.Jet.OLEDB.4.0;" _
& "DATA SOURCE=" _
& Server.MapPath(".\Emps.mdb;"))
DBDelete.CommandText ="Delete From Employees Where " _
& "EmployeeID = " _
& E.Item.Cells(1).Text
DBDelete.Connection = DBConn
DBDelete.Connection.Open
DBDelete.ExecuteNonQuery()
DBConn = New OleDbConnection("PROVIDER=" _
& "Microsoft.Jet.OLEDB.4.0;" _
& "DATA SOURCE=" _
& Server.MapPath(".\Emps.mdb;"))
DBCommand = New OleDbDataAdapter _
("Select EmployeeID, LastName, FirstName, " _
& "EmailAddress From Employees " _
& "Order By LastName", DBConn)
DBCommand.Fill(DSPageData, _
"Employees")
dgEmps.DataSource = _
DSPageData.Tables("Employees").DefaultView
dgEmps.DataBind
End If
End Sub

****stack trace*****
[OleDbException (0x80004005): Could not delete from specified tables.]

System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(Int32 hr)
System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult)
System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult)
System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult)
System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
System.Data.OleDb.OleDbCommand.ExecuteNonQuery()
ASP.Index_aspx.Click_Grid(Object Sender,
DataGridCommandEventArgs E) in http://localhost/WebApplication3/Index.aspx:66
System.Web.UI.WebControls.DataGrid.OnItemCommand(DataGridCommandEventArgs e)
System.Web.UI.WebControls.DataGrid.OnBubbleEvent(Object source, EventArgs e)
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
System.Web.UI.WebControls.DataGridItem.OnBubbleEvent(Object source, EventArgs e)
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e)
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
System.Web.UI.Page.ProcessRequestMain()

*************
it happens also when i wanna update or add new record.
can anybody tell me why i modify the database?
as i know the command.ExecuteNonQuery() method is used to execute Insert,
Update, and delete that do not return any row.
but the VS.Net ide indicates that this method(as integer) returns the number
of rows that are affected..
Why? I don't understand?
can anybody help me?