Error in import excel to sql query

check this code...:


protected void insertdata_Click(object sender, EventArgs e)
    {
        OleDbConnection oconn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("example.xls") + ";Extended Properties=Excel 8.0");
        try
        {
            OleDbCommand ocmd = new OleDbCommand("select * from [Sheet1$]", oconn);
            oconn.Open();
            OleDbDataReader odr = ocmd.ExecuteReader();
            string fname = "";
            string lname = "";
            string mobnum = "";
            string city = "";
            string state = "";
            string zip = "";
            while (odr.Read())
            {
                fname = valid(odr, 0);
                lname = valid(odr, 1);
                mobnum = valid(odr, 2);
                city = valid(odr, 3);
                state = valid(odr, 4);
                zip = valid(odr, 5);
                insertdataintosql(fname, lname, mobnum, city, state, zip);
            }
            oconn.Close();
        }
        catch (DataException ee)
        {
            lblmsg.Text = ee.Message;
            lblmsg.ForeColor = System.Drawing.Color.Red;
        }
        finally
        {
            lblmsg.Text = "Data Inserted Sucessfully";
            lblmsg.ForeColor = System.Drawing.Color.Green;
        }
    }
    protected string valid(OleDbDataReader myreader, int stval)//if any columns are found null then they are replaced by zero
    {
        object val = myreader[stval];
        if (val != DBNull.Value)
            return val.ToString();
        else
            return Convert.ToString(0);
    }
    protected void viewdata_Click(object sender, EventArgs e)
    {
        string dbConn = ConfigurationManager.ConnectionStrings["Excel"].ConnectionString;
        SqlConnection conn = new SqlConnection(dbConn);
       conn.Open();
        try
        {
            SqlDataAdapter sda = new SqlDataAdapter("select * from emp", conn);
            DataSet ds = new DataSet();
            sda.Fill(ds);
            GridView1.DataSource = ds;
            GridView1.DataBind();
        }
        catch (DataException de)
        {
            lblmsg.Text = de.Message;
            lblmsg.ForeColor = System.Drawing.Color.Red;
        }
        finally
        {
            lblmsg.Text = "Data Shown Sucessfully";
            lblmsg.ForeColor = System.Drawing.Color.Green;
        }
    }
    public void insertdataintosql(string fname, string lname, string mobnum, string city, string state, string zip)
    {
        string dbConn = ConfigurationManager.ConnectionStrings["Excel"].ConnectionString;
        SqlConnection conn = new SqlConnection(dbConn);
        conn.Open();
        SqlCommand cmd = new SqlCommand();
        cmd.Connection = conn;
        cmd.CommandText = "insert into emp(fname,lname,mobnum,city,state,zip) values(@fname,@lname,@mobnum,@city,@state,@zip)";
        cmd.Parameters.Add("@fname", SqlDbType.NVarChar).Value = fname;
        cmd.Parameters.Add("@lname", SqlDbType.NVarChar).Value = lname;
        cmd.Parameters.Add("@mobnum", SqlDbType.NVarChar).Value = mobnum;
        cmd.Parameters.Add("@city", SqlDbType.NVarChar).Value = city;
        cmd.Parameters.Add("@state", SqlDbType.NVarChar).Value = state;
        cmd.Parameters.Add("@zip", SqlDbType.NVarChar).Value = zip;
        cmd.CommandType = CommandType.Text;
      
        cmd.ExecuteNonQuery();
        conn.Close();
    }

go ahead and read this.

http://blogs.msdn.com/b/spike/archive/2008/07/23/ole-db-provider-microsoft-jet-oledb-4-0-for-linked-server-null-returned-message-unspecified-error.aspx