[Plugin: Contact Form 7] Adding a word count to message

I want to add this to an email message so that I have a word count before it submitted.. Thank you in advance for any suggestions of how to incorporate it with contact 7 would be greatly appreciated.

<textarea name="myMessage" onkeyup="wordcount(this.value)"></textarea>
<script type=""text/javascript"">
var cnt;
function wordcount(count) {
var words = count.split(/\s/);
cnt = words.length;
var ele = document.getElementById('w_count');
ele.value = cnt;
}
document.write("<input type=text id=w_count size=4 readonly>");
</script>