我有一个允许出租车预订的 html 表单，但它不应该允许及时预订！所以时间必须是当前或未来。
这是表格，我使用 datetime-local。
/* Here is the JavaScript validation for the datetime-local. */
var dateTime = document.getElementById("dateTime").value;
if (dateTime == "" || dateTime == null) {
booking.dateTime.focus();
document.getElementById("dateMessage").innerHTML = "Please select a date AND time, thankyou.";
return valid = false;
} else {
document.getElementById("destinationMessage").innerHTML = "";
}```
<form id="booking" action="">
<div id="firstNameMessage" class="red"></div>
<span class="red">*</span>First Name:
<input type="text" name="firstName" id="firstName">
<br>
<div id="lastNameMessage" class="red"></div>
<span class="red">*</span>Last Name:
<input type="text" name="lastName" id="lastName">
<br>
<div id="numberMessage" class="red"></div>
<span class="red">*</span>Contact …