Probability question.

[Domcsore]

Okay I've had so many ideas on how to do probability but when it comes to practice it's a little more difficult than I thought. Okay so what I am trying to create is a random advertisements script. So far I have this:

 

public function adImage(){
	$adimgLink[1] = 'template/template_files/ad_images/adhere.jpg';

	$noAds = (count($adimgLink));

	$randAd = rand(1,$noAds);

	echo '<img src="'.$adimgLink[$randAd].'" />';		

}

 

This works, however, I want it so customers can have a higher or lower probability of showing up depending on their budget they wish to spend on their advertisement. Any ideas? all help is appreciated =)

 

[SaMike]

How about you assign multiple numbers to ads?

Like numbers 1 to 10 would be ad1, and 11 to 15 would be ad2, then rand(1, 15)