SQL Query based on last 48 hours?

[PhilMcKrackon]

I have a PHP file that I run as a cron task every 24 hours. Can some one help with a tweak to the query to only select matches that have occurred between the time the query is executed and through 48 hours before?

PHP Code:

$urls = mysql_query("SELECT linkid,linkurl FROM adv_links ORDER by linkid ASC");
while ($urlrow = mysql_fetch_array($urls)) {
fwrite($file," ");
fwrite($file, $urlrow[1]);
fwrite($file, " | "); 
fwrite($file," ");
fwrite($file, $urlrow[0]);
fwrite($file," \n");
} 


How would I change

$urls = mysql_query("SELECT linkid,linkurl FROM adv_links ORDER by linkid ASC");

to accomplish this?

Any help would be appreciated!

Thanks,