function capitalize(sting) {
var words = string.split(" ");
for(var i = 0; i < words.length; i++) {
words[i] = words[i].charAt(0).toUpperCase() + words[i].slice(1);
}
return words.join(" ");
}
var string = "ajax cookie event object";
capitalize(string); // "Ajax Cookie Event Object"

words[i] = words[i].charAt(0).toUpperCase() + words[i].slice(1);