Checking Elements on a Form : Form HTML « Form Control « JavaScript DHTML

Checking Elements on a Form


<title>Online Registration</title>
     function checkFields() {
          var num = document.form1.elements.length
          var validFlag = true
          for (var i=0; i<num; i++) {
               if ((document.form1.elements[i].value == null || document.form1.elements[i].value == "") &&
                  (typeof document.form1.elements[i] != 'submit' || typeof document.form1.elements[i] != 'reset')){
                    validFlag = false;
                    alert("The " + document.form1.elements[i].name + " field is blank.")
                    break ;
          return validFlag;
// -->
<form name="form1" method="POST" onSubmit="return checkFields()">
    <input type=text size=25 maxlength=256 name="Username">
    Email address:
    <input type=text size=25 maxlength=256 name="EmailAddress"></p>
    <input type=submit value="Register"> 
    <input type=reset value="Clear">



Related examples in the same category

1.Adjusting a CGI Submission Action
2.Button Objects: Submit, Reset, and Button
3.Submitting Forms to the Server
4.Variables in Hidden form
5.Creating an Example Form for User Feedback
6.Accessing the Elements of a Form
7.Using the form.elements Array
8.form.reset() and form.submit() Methods
9.The onReset and onSubmit Event Handlers
10. Passing a Form Object and Form Element to Functions
11. Last-Minute Checking Before Form Submission
12.A Form for Entering a URL
13.Storing the last value using a Hidden object.
14.Methods and Properties of the Submit Object
15.Methods and Properties of the Reset Object
16.Properties of the Hidden Object
17.Methods and Properties of the Form Object
18.Client-Side JavaScript Objects and HTML Tags That Create Instances of Them
19.Using the document.forms Property
20.Use hidden field to store data