扩展接口

jQuery.fn.extend({
	check: function() {
		return this.each(function() { this.checked = true; });
	},
	uncheck: function() {
		return this.each(function() { this.checked = false; });
	}
});
$(function(){
	$("input[type=checkbox]").check().css("border","solid 1px red");
	$("input[type=radio]").uncheck().css("border","solid 1px blue");
});