Simple ASP computing program

Version 1:

HTML page

<! Doctype HTML public "-// W3C // dtd xhtml 1.0 transitional // en" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <HTML xmlns = "http://www.w3.org/1999/xhtml"> 
General Handler

<% @ Webhandler Language = "C #" class = "go" %> using system; using system. web; public class go: ihttphandler {public void processrequest (httpcontext context) {string strnum1 = context. request. form ["txtnum1"]; string strnum2 = context. request. form ["txtnum2"]; int x = 0, y = 0, Z = 0; If (! String. isnullorempty (strnum1 )&&! String. isnullorempty (strnum2) {If (Int. tryparse (strnum1, out X) & Int. tryparse (strnum2, out y) {z = x + y ;}} system. text. stringbuilder sbhtml = new system. text. stringbuilder (); sbhtml. append ("<HTML> 
Version 2:
Template placeholder:
Html

<! Doctype HTML public "-// W3C // dtd xhtml 1.0 transitional // en" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <HTML xmlns = "http://www.w3.org/1999/xhtml"> 
General Handler
<%@ WebHandler Language="C#" Class="go" %>using System;using System.Web;public class go : IHttpHandler {        public void ProcessRequest (HttpContext context) {        context.Response.ContentType = "text/html";        string path = context.Server.MapPath("computer.htm");        string sbHtml = System.IO.File.ReadAllText(path);                string strnum1 = context.Request.Form["txtnum1"];        string strnum2 = context.Request.Form["txtnum2"];        int x = 0,y=0,z=0;        if (!string.IsNullOrEmpty(strnum1) && !string.IsNullOrEmpty(strnum2))        {            if (int.TryParse(strnum1, out x) && int.TryParse(strnum2, out y))            {                z = x + y;            }        }        sbHtml= sbHtml.Replace("{num1}",x.ToString()).Replace("{num2}", y.ToString()).Replace("{num3}", z.ToString());        //context.Response.ContentType = "text/plain";        context.Response.Write(sbHtml);    }     public bool IsReusable {        get {            return false;        }    }}