Untitled

package main

import (
    "fmt"
    "html/template"
    "net/http"
)

var tpl *template.Template

func init() {
    tpl = template.Must(template.ParseGlob("templates/*.gohtml"))
}

func main() {
    http.HandleFunc("/", index)
    http.HandleFunc("/one", one)
    http.ListenAndServe(":8080", nil)
}

func index(w http.ResponseWriter, req *http.Request) {
    tpl.ExecuteTemplate(w, "index.gohtml", nil)
}

func one(w http.ResponseWriter, req *http.Request) {
    s := "This is one.gohtml"
    fmt.Fprintln(w, s)
}
=============================================================
<!DOCTYPE html>
<html>
<head>
  <title>Index</title>
</head>
<body>
  <h3>Alert!</h3>
  <h4>Make something to happen</h4>
  <script type="text/javascript">
    document.querySelector('h3').onclick = makeAlert;
    document.querySelector('h4').onclick = makeText;
    function makeAlert(){
      var xhr = new XMLHttpRequest();
      xhr.open('GET', '/one', true);
      xhr.onreadystatechange = function(){
        if(xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200){
          alert(xhr.responseText);
        }
      };
      xhr.send();
    }
    function makeText(){
      var xhr = new XMLHttpRequest();
      xhr.open('GET','/one',true);
      xhr.onreadystatechange = function(){
        if (xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200){
          var b = document.querySelector('body');
          var myHeadingOne = document.createElement('h5');
          var myHeadingOneText = document.createTextNode(xhr.responseText);
          myHeadingOne.appendChild(myHeadingOneText);
          b.appendChild(myHeadingOne);
        }
      };
      xhr.send()
    }
  </script>
</body>
</html>