In the following form if you leave the required sections blank, as you click submit, you will be forced to come back and fill this box in. Name: (* required) Comment: (*required) Email: The above form was created using the following code <form name="example" onSubmit="return validate()"> Name: <input type="text" size=20 name="name"> (* required) Comment: <textarea name="comment" rows=3 cols=30> (*required) Email: <input type="text" name="email" size=20> <input type="submit" name="submit" value="Submit"> </form> <script language=JavaScript> <!-- function validate() { if((document.example.name.value=="") || (document.example.comment.value=="")) { alert("You must fill in all of the required fields!") return false } } //--> </script> What's 'return true', 'return false' ? This is what's used to actually allow, or stop the form from submitting, respectively. This is how JavaScript controls the submitting of a form. By default, a form will return true (submit the form). I create function validate() that only returns true/false. You need return true/false to actually manipulate whether a form submits or not. || = or onSubmit is the event that invoke JavaScript upon clicking submit button.