Connection string for Excel File

For excel 2003

string connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Book2.xls;Extended Properties=\"Excel 8.0;HDR='YES'\"";

And For Excel 2007

 string connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Book1.xlsx        Extended Properties=\"Excel 8.0;HDR=YES;\"";