"override" in code below causes error detailed below. Why? and HowFix?

#region Web Form Designer generated code override protected void OnInit(EventArgs e) { // // CODEGEN: This call is required by the ASP.NET Web Form Designer. // InitializeComponent(); base.OnInit(e); } C:\Inetpub\wwwroot\WebApplication1\ReviewSetUp.aspx.cs(179): A namespace does not directly contain members such as fields or methods.