Animate Object with Jquery

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="jquery-ui.min.css">
    <script src="jquery.js"></script>
    <script src="jquery-ui.js"></script>
    <style>
        #panel {
            background-color: blue;
            width: 100px;
            height: 100px;
            position: absolute;
        }
    </style>
</head>

<body>
<button id="btn">Click to move my square box</button>
<br/> <br/> <br/> <br/> <br/>
<div id="panel">

</div>
<!--<script type="text/javascript" src="script.js">-->
<script>
    $(document).ready(function (){
        $("#btn").click(function (){
            $("#panel").animate({
                left:"300px"
            },300)
        })
    })
</script>
</body>

</html>