vb 2005 with excell 2007

[Mostafa Nabil]

hi

I am developing a program which needs to take information from excel document.

Here is my code (I did not complete it yet)
__________________________________________________ _____________

Dim exc As New Excel.Application
Dim book As New Excel.Workbook
Dim sheet1 As New Excel.Worksheet

book = exc.Workbooks.Open("D:\book1.xls")
sheet1 = book.Worksheets("sheet1")
sheet1.Columns.Find("Trip")



exc.Visible = True

__________________________________________________ ________

when I run this code It gives me an exception in the statemet " Dim sheet1 As New Excel.Worksheet" saying:
Com exception was unhandled
Retrieving the COM class factory for component with CLSID {00020819-0000-0000-C000-000000000046} failed due to the following error: 80040154.


when I deleted the statement " Dim book As New Excel.Workbook" and ran the program, the exception raised in the same place (empty space)!

help will be greatly appreciated