get_the_ID()-function

Hi!
Could somone help me out here? I want to put the class “selected” on the <a>-tag only on the post that is active.

I tried with this code, but it looks like somthing is wrong about the get_the_ID()-function…

<ul>
 <?php
 global $post;
 $p = $_GET['p'];

 $myposts = get_posts('category=1');
    foreach($myposts as $post):?>
         <li>
            <a href="<?php the_permalink();?>"
            <?php if($p == get_the_ID()) {echo ' class="selected"';}?>>
            <?php the_title();?></a>
         </li>
    <?php endforeach;?>
</ul>