<?php

function encryptZip($zip) {    
	$theSource = Array("8","v","w","M","P","I","N","o","Z","h","g","_","u","W","D","-","b","O","k","a","G","t","U","j","6","7","K","A","r","y","l","5","X","p","n","z","F","4","Y","d","2","9","q","V","s","0",".","e","H","c","x","Q","B","S");    	
	$r = '';    	
	while ($zip>0){   
		echo "Zip is currently $zip\n";
		$num = $zip % 53;    		
		$zip = ($zip - $num) / 53;    		
		$r .= $theSource[$num];    	
	}    	
	return $r;    
} 


echo encryptZip(90210);