Passing Text into URL from a Form - forms

Question

I'm trying to insert a variable collected from a form into a URL, but I don't want the "?variable=value" part of the URL.
<form action="http://www.example.com/<?php echo htmlspecialchars($_GET['entry']);?>/" method="GET">
<input type="text" value="" name="entry" id="entry">
<input type='submit'>
</form>
Is there any easy way to do this? I want the browser to go to the following URL when the user types "whatever"
http://www.example.com/whatever/
Edit:
I've changed the code to the following, which seems to work, but have I now introduced a script vulnerability?
<form onSubmit=" location.href = 'https://www.example.com/' + document.getElementById('entry').value + '/' ; return false; ">
<input type="text" value="" name="entry" id="entry" placeholder="Your Promo Code">
<input name="promoSubmit" type="submit" value="Buy Now">
</form>

Answer 1

you could use javascript for this kind of tasks, i don't see why would you involve server side for such thing
but the easiest answer will be like:
<script>
function go(){
window.location='http://www.example.com/'+document.getElementById('url').value;
}
</script>
<input type='text' id='url'>
<button id='btn_go' onclick='javascript:go();'>Go</button>