Untitled

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>

    <form >
        value 1= <input type="text" id="Value1">
        value 2= <input type="text" id="Value2">
operator:
<select id="operator">
    <option value="add" >Add</option>
    <option value="min" >minus</option>
    <option value="div" >divide</option>
    <option value="mul" >multiply</option>
</select>
<button type="button" onclick="calc()"> Calculate </button>
</form>

<div id="result"></div>


</body>
<script src="main.js"></script>
</html>