基于特定选定输入的Javascript警报（下拉列表）

我的Javascript知识非常有限，因此需要一些帮助，请：

我有以下功能：

$('#addDialog').dialog({
        autoOpen: false,
        width: 500,
        buttons: {
            "Add": function() {

                //alert("sent:" + addStartDate.format("dd-MM-yyyy hh:mm:ss tt") + "==" + addStartDate.toLocaleString());
                var eventToAdd = {
                  //title: $("#addEventName").val(),
                    title: $("#addEventSalesPerson option:selected").text(),
                    description: $("#addEventDesc").val(),
                    start: addStartDate.format("dd-MM-yyyy hh:mm:ss tt"),
                    end: addEndDate.format("dd-MM-yyyy hh:mm:ss tt"),
                    salesperson: $("#addEventSalesPerson option:selected").text(),
                    eventPostCode: $("input[id$=addEventPostCode]").val(),
                    eventname: $("#addEventEventName option:selected").text()
                };

                if ($("input[id$=addEventPostCode]").val().length < 5) {
                    alert("Post code cannot be blank and must contain a minimum of 5 characters");

                }

                else {
                    //alert("sending " + eventToAdd.title);

                    PageMethods.addEvent(eventToAdd, addSuccess);
                    $(this).dialog("close");
                }

            }

        }
    });

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更改以下行

if ($("input[id$=addEventPostCode]").val().length < 5) {

---

如果任何字符串匹配，结果将为false，If将不会触发警报。

如果我选择假日或疾病，它仍然要求提供邮政编码。这是一行代码：

if（$（$input[id$=addEventPostCode]）.val（）.length<5&！（$（“#addeventsalesson option:selected”）.text（）=“Holiday”| |$（“#addeventsalesson option:selected”）{alert（“Post code不能为空，必须至少包含5个字符”）

if ($("input[id$=addEventPostCode]").val().length < 5) {

if ($("input[id$=addEventPostCode]").val().length < 5 && !($("#addEventSalesPerson option:selected").text() == "Holiday" || $("#addEventSalesPerson option:selected").text() == "Sickness")) {

! //This is Not
( //Parenthesis group expressions together so the not works on the result of the expressions inside
$("#addEventSalesPerson option:selected").text() == "Holiday" //This checks if selected text matches string
|| //This means Or
$("#addEventSalesPerson option:selected").text() == "Sickness" //This checks if selected text matches string
)