text: var myHeading = document.querySelector('h1');
  var id = localStorage.getItem('id');
  
  
  
  function getIDPW(){
    var id =prompt('ID 입력','');
    var password = prompt(id + '가 사용할 초기 비번 입력','');
    localStorage.setItem('id',id);
    localStorage.setItem('password',password);
    }
  
  
  
    
    var passwordSystem = '1234'
  var password = prompt('PW 입력','')
  if (password ===passwordSystem){
      alert('로그인 성공')
      var id = localStorage.getItem('id');
  var heading= document.querySelector('h1');
  heading.innerHTML = id + 'HomePage';
      
  }
  else alert('로그인 실패')
         
  var myButton = document.querySelector('button');
  var myHeading = document.querySelector('h1');
  
      myButton.onclick = function() {
        getIDPW();
      }  
  