I have an html form with multiple fields. Some of the fields are required, others are not. I have a JavaScript validation form that will send an alert if a field is empty. However, I only want it to send an alert if a required field is empty. How do I signify which fields in the form should cause the alert message to pop up?


Tom Tolleson

You can test the field by className in your javascript and give all required fields the same class name.

Something like this

var form = document.getElementById('myform');

for ( var i = 0; i < form.length; i ++ ) {
  if ( /required/.test( form[i].className ) {
    if ( !form[i].value ) { // might have to tweek this some ...
      alert( 'You missed a required field: ' + field.name );
      return false; // test failed, abort form submit

// all fields passed the test ...
return true; // or maybe use

What a required field might look like

<input type="text class="required" name="First Name" />

This is off the top of my head, so I don't know it will work "out of the box" but it's the general idea anyway.

Hope this helps