Here's a very simple jQuery example :
http://www.ihaols.com/geo.html
Code :
$(function(){
$('#btn').click(function(){
var address = encodeURIComponent($('#k').val());
$.get('http://maps.google.com/maps/api/geocode/json?address='+ address + '&sensor=false', function(data){
console.log(data);
var l = data.results[0].geometry.location;
var v = l.lat + ',' + l.lng;
$('#r').val(v);
});
});
});
But this code doesn't work in IE7/8, I've already include json2.js
in it.