ASP.NET : Display the number of visits on a page

public partial class _Default : System.Web.UI.Page
{
static int counter = 0;
private static readonly Object lockObj = new Object ();
protected void Page_Load(object sender, EventArgs e)
{
++counter;
lock (lockObj)
{
Application["SiteCounter"] = counter;
}
Response.Write("This page is visited "+ counter.ToString() + " times");
Response.Write("since restart of IIS or this webapplication");

}
}