//using System.Globalization;
CultureInfo culture = new CultureInfo("en-AU");
DateTime week_start = Convert.ToDateTime("27/07/2011", culture);

int intValue = 1512;
string stringValue = intValue.ToString("#,#", CultureInfo.GetCultureInfo(Thread.CurrentThread.CurrentCulture.Name));
/* Result in US English (en-US) will be 1,512
   Result in Swedish (sv-SE) will be 1 512 */

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Resources;
using System.Text;
using System.Threading;
using System.Globalization;