Cấu trúc file Aspx trả về cho Ajax

- Dạng text / html
Response.Clear();
Response.ContentType = "text/HTML";
Response.Write(ff);
Response.End();

- Dạng json
Response.Clear();
Response.ContentType = "application/json";
Response.Write(ff);
Response.End();

- Dạng xml
Response.Clear();
Response.ContentType = "text/xml";
Response.Write(ff);
Response.End();

Ví dụ:
 protected void Page_Load(object sender, EventArgs e)
 {
        
        Response.Clear();
        Response.ContentType = "text/HTML";
        Response.Write("noi dung");
        Response.End();
}