PHP generate Random String

random_generator.php

<?php 
function create_costumer_key($length=8,$use_upper=1,$use_lower=1,$use_number=1,$use_custom=""){
	$upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	$lower = "abcdefghijklmnopqrstuvwxyz";
	$number = "0123456789";
	if($use_upper){
		$seed_length += 26;
		$seed .= $upper;
	}
	if($use_lower){
		$seed_length += 26;
		$seed .= $lower;
	}
	if($use_number){
		$seed_length += 10;
		$seed .= $number;
	}
	if($use_custom){
		$seed_length +=strlen($use_custom);
		$seed .= $use_custom;
	}
	for($x=1;$x<=$length;$x++){
		$password .= $seed{rand(0,$seed_length-1)};
	}
	return($password);
}
?>