I had a search around and found the following which is exactly what I was looking for. I have been trying to add a different subject in for each of the mail addresses but not too sure how it works. If anyone has any pointers, that would be great.
Thanks
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>New Page 1</title>
</head>
<body>
<!-- Add this to the <head> section -->
<script language="JavaScript" type="text/javascript">
function GotoURL() {
location.href="mailto:" + document.getElementsByName("picker")[0].value;
}
</script>
<!-- Add this to the <body> section -->
<!-- Obviously, you should edit the code to show your own URLs, and you can change the style attributes to suit your colour scheme -->
<form name="go" id="go">
<select name="picker" id="picker" style="font-family: Arial, Helvetica, sans-serif;">
<option value="hi@hi.com" style="background-color: #e0e0e0;" selected>Home Page</option>
<option value="hello@hello.com">Contents</option>
<option value="goodbye@goodbye.com" style="background-color: #e0e0e0;">Webmaster</option>
<option value="lol@lol.com">Tools I use</option>
</select>
<input type="button" value="Go" style="color:#FFFFFF;background:#CC9900" title="Click to Go" onClick="GotoURL()">
</form>
</body>
</html>