function getXHR()
{
	var xhr= null;
	if (window.XMLHttpRequest)
	{	// Mozilla
		xhr=new XMLHttpRequest();
	}
	else
	{
		if (window.ActiveXObject)
		{	// C'est Internet explorer < IE7
			try
			{
				xhr=new ActiveXObject("Msxml2.XMLHTTP");
			}
			catch(e)
			{
				try
				{
					xhr=new ActiveXObject("Microsoft.XMLHTTP");
				}
				catch(e)
				{
					xhr=null;
				}
			}
		}
	}
	  
	return xhr;
}