how to call a function from another function in Jquery

how to call a function from another function in Jquery

<script>
$(document).ready(function(){
//Load City by State
$('#billing_state_id').live('change', function() {
//do something
});
$('#click_me').live('click', function() {
//do something
//need to recall $('#billing_state_id').live('change', function() {
but how?
});
});
</script>
Load City by State working fine but i don't know whether it's possible or
not to call it within another function like $('#click_me').live('click',
function().