Untitled

<!DOCTYPE html>
<html>
<head>
    <title>NubyChan</title>
    <link rel="stylesheet" type="text/css" href="css/bootstrap.min.css">
    </head>
<body>
<button class="btn btn-danger btn-block" onclick="klik()">Submit</button>
<script>
    function klik(){
        alert("Hello NubyChan!")
    }
</script>
</body>
</html>