greasemonkey translator with double click

translator.js

// ==UserScript==
// @name        clicktrans
// @namespace   translator
// @version     1
// @include      *://*/*
// @require http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js
// @grant       GM_addStyle

// ==/UserScript==
console.log('script runs');
var txt = '';
var api = 'https://translate.googleapis.com/translate_a/single?client=gtx&sl=auto&tl=tr&dt=t&q=';
body = document.getElementsByTagName('body') [0];
body.addEventListener('dblclick', function (e) {
  translate(window.getSelection().toString(),e)
}, false);
body.addEventListener('click', function () {
  $("#kwdHelpInfo").remove();
}, false);
function translate(txt,event) {
  txt = txt.toLocaleLowerCase();
  console.log(txt);
  url = api + txt;
  fetch(url).then(function (response) {
    return response.json();
  }).then(function (data) {
    console.log(data);
    showtranslation(data[0][0][0],event);
  }).catch (function () {
    console.log('Booo');
  });
}
function showtranslation(data,e) {
  console.log(data);
  var settingsDiv = '<div style="position:fixed;top:topypx;left:topxpx;background:#f8b035;font-size:180%; border-radius:1ex;padding-top:11px;padding-right:15px;padding-bottom:15px;padding-left:15px; z-index: 777;" id="kwdHelpInfo">'+data+'</div>';
  settingsDiv = settingsDiv.replace("topx",e.clientX+20);
  settingsDiv = settingsDiv.replace("topy",e.clientY+20);
  console.log(settingsDiv)
  $('body').append(settingsDiv);
}