我怎样才能让 Javascript 显示我的 JavaScript 代码中的错误，为什么我的提交按钮不起作用？

Question

 var $ = function(id) { return document.getElementById(id); } var submitForm = function() { var FirstName = $("firstName").value; var OrderNumber = $("orderNumber").value; var DateOfOrder = $("date_of_order").value; var EmailAddress = $("email_address").value; var isValid = true; if (FirstName !== "Cherry" && FirstName !== "Micheal" && FirstName !== "Sandra" && FirstName !== "Cookie") { $("firstname_error").firstChild.nodeValue = "This person does not exist."; isValid = false; } else { $("firstname_error").firstChild.nodeValue = ""; } if (OrderNumber !== 3134 && OrderNumber !== 4234 && OrderNumber !== 9234 && OrderNumber !== 3566) { $("orderNumber_error").firstChild.nodeValue = "Invalid Order Number."; isValid = false; } else { $("orderNumber_error").firstChild.nodeValue = ""; } if (DateOfOrder !== 12 - 07 - 23 && DateOfOrder !== 15 - 04 - 24 && DateOfOrder !== 16 - 02 - 01 && DateOfOrder !== 14 - 01 - 12) { $("date_of_order_error").firstChild.nodeValue = "Date doesn't exist in system"; isValid = false; } else { $("date_of_order_error").firstChild.nodeValue = ""; } if (EmailAddress !== "cherryjackson@gmail.com" && EmailAddress !== "michealroberts@yahoo.com" && EmailAddress !== "sandrabell@hotmail.com" && EmailAddress !== "cookiedanny@outlook.com") { $("email_address_error").firstChild.nodeValue = "The email doesn't exist"; isValid = false; } else { $("email_address_error").firstChild.nodeValue = ""; } if (isValid) { //submit the form if all entries are valid $("cookie_form").submit(); } } window.onload = function() { $("form_submission").onclick = submitForm; $("email_address").focus(); }

 body { background-color: #FBFBE8; } /* Tells HTML5 to find the font-type-face that my OS has and then use that for heading 1 and also centers the first heading */ h1 { font-family: Arial, Helvetica, sans-serif; text-align: center; } /* Tells HTML5 to use any of the font-types for my first paragraph in HTML source file if one is not available. Also clears some white space from the left margin of the paragraph and finally tells it to give that paragraph a size of 20 pixels. */ p { font-family: Arial, Helvetica, sans-serif; padding: 20px; font-size: 20px; } label { float: left; width: 11em; text-align: right; font-family: Arial, Helvetica, sans-serif; color: #800000; } input { margin-left: 1em; margin-bottom: .5em; } span { color: red; } .field_set_1 { border-color: purple; border-style: solid; } #form_submission { background-color: black; color: white; } legend { font-family: Arial, Helvetica, sans-serif; color: blue; } /* All of the classes are just for positioning and floating the four same images around the form input information */ .Wrap1 { float: right; margin: 40px; width: 200px; height: 200px; } .Wrap2 { float: left; margin: 40px; width: 200px; height: 200px; } .clearfix { clear: both; }

 <h1>Cookie Order Form</h1> <p>This form is a cookie order form for customers that purchased cookies from Daron's Cookies Company and the following below must be filled out in order for each customer to receive a final message that tells them when their order will be ready.</p> <IMG class="Wrap1" SRC="cookie.gif" alt="cookie"> <IMG class="Wrap2" SRC="cookie.gif" alt="cookie2"> <!--The customer will be sent to the HTML page named "submit form.html" after they click the "Submit this Form" button. The code below does this. --> <div> <form id="cookie_form" name="cookie_form" action="submit form.html" method="get"> <fieldset class="field_set_1"> <!-- Below sets the title of the form--> <legend>Customer Order Form Information:</legend> <!-- Creates the first left label to specify what should be placed in the text box the the right of the label. The rest below does the same.--> <label for="firstName">First Name:</label> <input type="text" id="firstName" name="firstName"> <span id="firstname_error">*</span> <br> <label for="orderNumber">Order Number:</label> <input type="text" id="orderNumber" name="orderNumber"> <span id="orderNumber_error">*</span> <br> <label for="date_of_order">Date of Order:</label> <input type="text" id="date_of_order" name="date_of_order"> <span id="date_of_order_error">*</span> <br> <label for="email_address">Email Address:</label> <input type="text" id="email_address" name="email_address"> <span id="email_address_error">*</span> <br> <label>&nbsp;</label> <input type="button" id="form_submission" value="Submit this Form"> </fieldset> </form> </div> <div class="clearfix"> </div> <IMG class="Wrap1" SRC="cookie.gif" alt="cookie"> <IMG class="Wrap2" SRC="cookie.gif" alt="cookie2">

I have been working on this for hours. I am trying to figure out why won't my JavaScript code won't display the error message in the form when customers enter invalid order Numbers, incorrect order dates, or names that system can't detect. etc. Can someone pinpoint in the right direction of why my code doesn't work for the form and why won't it go to the next page when I click on the 'submit this form' button.

Answer 1

The value coming from your input elements doesn't match to orderNumber and date of birth. puting them in quotes (inside condition check) will solve the issue.

if(DateOfOrder !== "12-07-23" && DateOfOrder !== "15-04-24" &&
   DateOfOrder !== "16-02-01" &&  DateOfOrder !== "14-01-12")
{....}

Working Example