Contact Form 7 image preview

Hi!
I want to make a form with the contact form 7 plugin and i want to make in the dorm an uploader
input to upload images and I want to insert a preview to the end of the form. I have a javascript
code for this:

<script type="text/javascript" src="http://iphonefanatic.hu/wp- <script type="text/javascript"> <!-- function onFileLoad(e) { $('#preview').append('<img class="preview" src="'+e.target. } function displayPreview(files) { var reader = new FileReader(); reader.onload = onFileLoad; reader.readAsDataURL(files[0]); } //--></script>

and the picture appears where the
<span id="preview"></span>
code It’s only working when I put the page’s source to an HTML file.
Can anyone help me?
(sorry for my bad english)