Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<body>

E-mail: <input type="email" id="myEmail"><br><br>

<button onclick="disableBtn()">Disable Email Field</button>
<button onclick="undisableBtn()">Undisable Email Field</button>

<script>
function disableBtn() {
    document.getElementById("myEmail").disabled = true;
}

function undisableBtn() {
    document.getElementById("myEmail").disabled = false;
}
</script>
</body>
</html>