jQuery Plugins

addItems.js

$.fn.addItems = function(data) {
	return this.each(function() {
		var list = $(this)
		list.empty()
		if (data.length != []) {
			$.each(data, function(index, text) {
				list.append("<option value="+index+">"+text+"</option>")
			})
		} else {
			list.append("<option>Nenhuma opção encontrada</option>")
		}
	})
}

changeHandler.js

$.fn.changeHandler = function(options) {
	var opts = $.extend({}, $.fn.changeHandler.defaults, options)
	this.bind("change", opts, function(event) {
		var selected = $("option:selected", this).val()
		var postData = {}
		postData[event.data.postName] = selected
		$.ajax({
			type: "POST",
			url: event.data.url,
			data: postData,
			success: function(data) {
				$(event.data.updateId).addItems(data)
				$(event.data.updateId).removeAttr('disabled')
			}
		})
		return false
	})
}