Doubt related to PHP Cookies
<p>I have a doubt, I will appreciate  if you can clear it .</p>

<p><strong>COOKIES</strong></p>

<p>What are cookies? When described as entities, which is how cookies are often referenced
in conversation, you can be easily misled. Cookies are actually just an extension of the
HTTP protocol. Specifically, there are two additional HTTP headers: Set-Cookie and
Cookie.The operation of these cookies is best described by the following series of
events:</p>

<ol>
<li><p>Client sends an HTTP request to server.</p></li>
<li><p>Server sends an HTTP response with Set-Cookie: foo=bar to client.</p></li>
<li><p>Client sends an HTTP request with Cookie: foo=bar to server.</p></li>
<li><p>Server sends an HTTP response to client.</p></li>
</ol>

<p>Thus, the typical scenario involves two complete HTTP transactions. In step 2, the server
is asking the client to return a particular cookie in future requests. In step 3, if the
user’s preferences are set to allow cookies, and if the cookie is valid for this particular
request, the browser requests the resource again but includes the cookie.</p>

<p><em><strong>Now my question is.......</em></strong></p>

<p>why you cannot determine whether a user’s preferences are set to allow cookies during the first request????</p>
