Randomize by percentage

[gibigbig]

I am making an online game and when making a character, I want the gender chosen to be random, but controlled by a percentage.

 

Example:

$male = 80; // in %
$female = 20; //in %

   

Is there a function that will output "male" or "female" depending on the percentage of odds. Or do I have to make my own

[gizmola]

$gender = (rand(1, 10) > 2) ? 'M'  : 'F';