表单中回车选择下一个文本框，兼容IE,Chrome

        document.onkeydown = function (evt) {
            var isie = (document.all) ? true : false;
            var key;
            var srcobj;
            if (isie) {
                key = event.keyCode;
                srcobj = event.srcElement;
            }
            else {
                key = evt.which;
                srcobj = evt.target;
            }
            if (key == 13 && srcobj.type != 'button' && srcobj.type != 'submit' && srcobj.type != 'reset' && srcobj.type != 'textarea' && srcobj.type != '') {
                if (isie) {
                    event.keyCode = 9;
                }
                else {
                    var el = getNextElement(evt.target);
                    if (el.type != 'hidden')
                        el.focus();
                    else
                        while (el.type == 'hidden')
                            el = getNextElement(el);
                    el.focus();
                    return false;
                }
            }
        }
        function getNextElement(field) {
            var form = field.form;
            for (var e = 0; e < form.elements.length; e++) {
                if (field == form.elements[e])
                    break;
            }
            return form.elements[++e % form.elements.length];
        }