app.js

var tablinks = document.getElementsByClassName("tab-links");
var tabcontents = document.getElementsByClassName("tab-contents"); 

function opentabe(tabname){
    for(tablelink of tablinks){
        tablelink.classList.remove("active-link")
    }
    for(tabcontent of tabcontents){
        tabcontent.classList.remove("active-tab")
    }
    event.currentTarget.classList.add("active-link")
    document.getElementById(tabname).classList.add("active-tab")
}

var sidemenu = document.getElementById("sidemenu");
function openmenu(){
    sidemenu.style.right = "0"
}
function closemenu(){
    sidemenu.style.right = "-200px"
}

  const scriptURL = 'https://script.google.com/macros/s/AKfycbz-kZVwXB192Mvg4_ZjvMdqRYDpLAoU8DQMFEdfXrF7uNsX0SUfSo32Q6NhJv38XZw/exec'
  const form = document.forms['submit-to-google-sheet']
  const msg = document.getElementById('msg')
  form.addEventListener('submit', e => {
    e.preventDefault()
    fetch(scriptURL, { method: 'POST', body: new FormData(form)})
      .then(response => {
        msg.innerHTML= "Thank for your message <br> message sent successfully"
        setTimeout(function(){
            msg.innerHTML = ""
        },4500)
        form.reset()
      })
      .catch(error => console.error('Error!', error.message))
  })