string connString = ConfigurationManager.ConnectionStrings["xls"].ConnectionString;
        // Create the connection object
        OleDbConnection oledbConn = new OleDbConnection(connString);
        try
        {
            // Open connection
            oledbConn.Open();
 
            // Create OleDbCommand object and select data from worksheet Sheet1
            OleDbCommand cmd = new OleDbCommand("SELECT * FROM [Sheet1$]", oledbConn);
 
            // Create new OleDbDataAdapter
            OleDbDataAdapter oleda = new OleDbDataAdapter();
 
            oleda.SelectCommand = cmd;
 
            // Create a DataSet which will hold the data extracted from the worksheet.
            DataSet ds = new DataSet();
 
            // Fill the DataSet from the data extracted from the worksheet.
            oleda.Fill(ds, "Customer");
 
            // Bind the data to the GridView
            GridView1.DataSource = ds.Tables[0].DefaultView;
            GridView1.DataBind();
        }
        catch
        {
        }
        finally
        {
            // Close connection
            oledbConn.Close();
        }