vapor-press1.html

<!doctype html>
<html>
<head>
    <!--Step 2-->
    <script src="https://d3js.org/d3.v4.min.js"></script>
    <link rel="stylesheet" type="text/css" href="style.css" />  
</head>
    
<body>   
<!--Step 2-->
<svg width="1000" height="700"></svg>
    
<script src="app1.js"></script>">
<center>    
    <button class="button button1" onclick="myVolta()">Volta</button>
</center>
</body>
</html>