Is it possible to hide a url?

Question

The url in address bar like this: myPage.jsp?rcId=25
maybe changed by user into myPage.jsp?rcId=109
So the user could see other's information.
There is a good idea used in the hotmail, that when you click on one of messages list, NO url appears in browser address bar.
Can any one share a solution.
Thank you all.

Answer 1

Thanks Guys
Please let me say, Some users have granted access to intranet web-based application. every user have check a relevant information concerning him, e.g. "internal e-mails subsystem" shows messages for every user by clicking a link which appears in
address bar, the problem is any change in parameters will show other user message.
To solve this problem I did this:
<form name="form01" action="mailSys.jsp" method="post">
     myMessage
<input type="hidden" name="mId" value="<%=mId%>" />
</form>     
<script language="javascript">
function goShow() {
document.form01.submit();
</script>
Now, Is it good to do this in a list of message "Limited 20" retrieving by a vector? you know a <form> will generated in every record.