Use this simple code for get preview an image before and after upload.
<script type="text/javascript">
function readURL(input) {
if (input.files && input.files[0]) {
var reader = new FileReader();
reader.onload = function (e) {
$('#blah').attr('src', e.target.result);
}
reader.readAsDataURL(input.files[0]);
}
}
</script>
<body>
<form id="form1" runat="server">
<input type="file" onchange="readURL(this);" />
<img id="blah" src="#" alt="your image" />
</form>
</body>