<html>
<head>
<style>
/* Style the tab */
.tab {
overflow: hidden;
border: none;
}

/* Style the buttons that are used to open the tab content */
.tab button {
background-color: yellow;
float: left;
border: 1px solid #ccc;
outline: none;
cursor: pointer;
padding: 14px 16px;
transition: 0.3s;
}

/* Change background color of buttons on hover */
.tab button:hover {
background-color: #ddd;
}

/* Create an active/current tablink class */
.tab button.active {
background-color: #ccc;
}

/* Style the tab content */
.tabcontent {
display: none;
padding: 6px 12px;
border: 1px solid #ccc;
border-top: none;
}
</style>

// Get all elements with class="tabcontent" and hide them
tabcontent = document.getElementsByClassName("tabcontent");
for (i = 0; i < tabcontent.length; i++) {
tabcontent[i].style.display = "none";
}

// Get all elements with class="tablinks" and remove the class "active"
tablinks = document.getElementsByClassName("tablinks");
for (i = 0; i < tablinks.length; i++) {
tablinks[i].className = tablinks[i].className.replace(" active", "");
}

// Show the current tab, and add an "active" class to the button that opened the tab
document.getElementById(cityName).style.display = "block";
evt.currentTarget.className += " active";
}

</script>
</head>
Copyright © <script type="text/javascript">
copyright=new Date();
update=copyright.getFullYear();
document.write("2018 - " + update + " " + " ");

</script>

<div class="tab">
<button class="tablinks" onclick="openCity(event, 'London')">London</button>
<button class="tablinks" onclick="openCity(event, 'Paris')">Paris</button>
<button class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</button>
</div>

<div id="London" class="tabcontent">
<h3>London</h3>
<p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
<h3>Paris</h3>
<p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
<h3>Tokyo</h3>
<p>Tokyo is the capital of Japan.</p>
</div>
</html>