<?php
$randomQ = @mysql_query( "SELECT * FROM `Pastes` ORDER BY RAND() LIMIT 1" );
if ( mysql_num_rows( $randomQ ) == 0 )
{
    echo "No pastes are available to show a random paste.";
}
else
{
    $randomA = @mysql_fetch_array( $randomQ );
    echo '<a href="pastes.php?id=' . $randomA["PasteID"] . '">Random Paste</a>';
}
?>