public void UploadData()
        {
            string uploadedFilePath = UploadFile();
            string strConnectionString = "Provider Name=" + uploadedFilePath;

            DataSet ds = new DataSet();
            //A-Z is column number of excel file
            OleDbDataAdapter da = new OleDbDataAdapter("SElect * from [A-Z]", strConnectionString);

            da.Fill(ds);
            GridView1.DataSource = ds;
            GridView1.DataBind();
        }
        private string UploadFile()
        { 
            //write code here for upload
            string uploadedFilePath; //Assign uploaded physical path
            return uploadedFilePath;
        }