I have a Banner site in PHP

I think it can be done via giving conditions but I don't not exactly how to do that.

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(I want to display 10 banner from 10 different users)

If the visitors rich the site using an affiliate id, then I want the banners from
that affiliate to display on the firs 3 spots. If the affilaite does not have banners
on his account added yet, or does not have all 3, then I want banners from
admin to fill the remainig spots.

If the visitor rich the site without and affilaite id, then I want 3 banners from
admin to display on the firs 3 spots.

Need spots 4-10 to ramdoly display all members banners.

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Please help me ASAP

 

this can be done like this...(according to what i understood so far)
user visit link is something like this...
www.yoursite.com/affiliate.php?affi=1234
if(isset($_POST['affi'])){
echo '<img src="www.yoursite.com/images/affiliate_img.png"/>';
}
else{
echo '<img src="www.yoursite.com/images/default_img.png"/>';
}

i think you get the idea.
you can expand/modify it according to your requirements.