Progressbar in JavaScript

"use strict"

document.querySelector("#gomb").addEventListener("click", (evt) => {

    mozgas()

    function mozgas() {

        const elem = document.getElementById("folyamatBar")
        let width = 0
        let id = setInterval(frame, 100)

       function frame() {
            if (width == 100) {
                clearInterval(id)
                width = 0
                alert("Folyamat kész")
            }

            else {

                width++
                elem.style.width = width + '%'

            }


        }

    }


})

  <!DOCTYPE html>
<html lang="hu">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="folyamatJelzo">
        <div id="folyamatBar" style="background-color: aqua; width: 10%;">


        </div>
    </div>

    <button type="button" class="btn btn-primary" id="gomb">Folyamat</button>


    <script src="./asd.js">

    </script>
</body>
</html>