Javascript不会停止php表单提交

Question

Javascript gives error window, but it won't stop the form submission. I'm stumped at this point and can't find an exact answer. Here is the code, thanks:

    function newNameValidate() {
        var x = document.forms["checkIn"]["newName"].value;
        if (x==null || x=="") {
        alert("Tech name must be filled out");
        return false;
    }
        return true;
    }

Here is the HTML:

<form name="checkIn" onsubmit="newNameValidate(checkIn)" action="check_in_complete.php" method="POST">

<input type ="submit" class="input" value="CHECK IN">

Answer 1

您必须返回函数的值onclick =“ return foo（）;”

Answer 2

As others have said, you need to return the value returned from the function, but a better option is to use unobtrusive JavaScript:

<form name="checkIn" action="check_in_complete.php" method="POST">

Script:

window.onload = function() { 
    document.forms["checkIn"].onsubmit = newNameValidate;
}

Answer 3

It can be done like: 
<form name="checkIn" id="checkIn" action="check_in_complete.php" method="POST">
<input type ="button" class="input" value="CHECK IN"  onclick="newNameValidate()">
</form>

<script>
function newNameValidate() {
        var x = document.forms["checkIn"]["newName"].value;
        if (x==null || x=="") {
        alert("Tech name must be filled out");
        return false;
    }else{
            checkIn.submit();
        }
    }
</script>