Hi zaghmout.
First make sure that your page declaration (or define it in web.config) is
Code:
<%@ Page Culture="auto" UICulture="auto" %>
That ensures that the culture that the browser is using is the one ASP.NET is responding to (you can also specify a culture if you want).
Second look at how your browser is configured. If you use IE6 it's: Tools -> Internet settings -> the general tab and then click the Language button. The highest ranking language is the one the browser sends to the web server. If FF: Tools -> Settings -> the general tab and then click the "Choose..." button in the Language fieldset. The same language rule applies to both browsers.
Hope this helps!
- mega
Moving to C# .NET