Javascript Form How to - Last-Minute Checking Before Form Submission

Question

We would like to know how to last-Minute Checking Before Form Submission.

Answer


<html> 
<head> 
<script type="text/javascript"> 
function checkForm(form) { <!--  w ww  . ja  va  2  s .co m-->
    for (var i = 0; i < form.elements.length; i++) { 
        if (form.elements[i].type == "text" && form.elements[i].value == "") { 
            document.write("Fill out ALL fields."); 
            return false; 
        } 
    } 
    return true; 
} 
</script> 
</head> 
<body> 
    <form onsubmit="return checkForm(this)"> 
        Please enter all requested information:<br> 
        First Name:<input type="text" name="firstName"><br> 
        Last Name:<input type="text" name="lastName"><br> 
        Rank:<input type="text" name="rank"><br> 
        Serial Number:<input type="text" name="serialNumber"><br> 
        <input type="submit"> 
    </form> 
</body> 
</html>

The code above is rendered as follows: