@Xeon06, nice but just as a fyi for those that read this thread and tried like me...
when returning the array from php => json_encode($theArray). converts to a string which to me isn't easy to manipulate esp for soft js users like myself.
Inside js, you are trying to get the array values and/or keys of the array u r better off using JSON.parse as in var jsArray = JSON.parse(data) where data is return array from php. the json encoded string is converted to js object that can now be manipulated easily.
e.g. foo={one:1, two:2, three:3} - gotten after JSON.parse
for (key in foo){ console.log("foo["+ key +"]="+ foo[key]) } - prints to ur firebug console. voila!