Question: In my page, I'm using a javascript function

```
<script> 
function redirect(){ 
    window.location="hurray.php";
}
</script>

```

Calling the function from the line below.

```
<input id="search_box" name="textbox" type="text" size="50" maxlength="100" onkeypress="redirect()" />

```

Now I want to make it sure that the page 'hurray.php' is visited only from this action. If I typed the direct URL to 'hurray' page, I should not be able to visit this page, rather redirect it to this previous page.

Answer: 
Make an AJAX call to a PHP function that will set a variable in the session. When the AJAX call returns response redirect the user to this page and check for the session variable. You can delete it if you do not want the user to be able to visit it again for this session.
Extend your function so it sets a cookie via "document.cookie", then check via JS ,PHP or whatever on the target page if the cookie is set and redirect somewhere else if not, quite simple. **Of Course thats not really secure!**