Two ways to prevent form submission using JavaScript _javascript tips

In JavaScript, there are two ways to block the default submission behavior of a form, namely:

(1) return False

Sample code

<form name= "LoginForm" action= "Login.aspx" method= "POST" >
 <button type= "Submit" value= "Submit" id= " Submit ">Submit</button>
</form>

<script>
 var submitbtn = document.getElementById ("submit");

 Submitbtn.onclick = function (event) {
  alert ("preventdefault!");
  return false;
</script>

(2) using Preventdefault ()

In standard browsers, the default behavior of the browser is blocked, event.preventDefault() and in ie6~8, returnValue attributes are used to implement it.

Sample code

<form name= "LoginForm" action= "Login.aspx" method= "POST" >
 <button type= "Submit" value= "Submit" id= " Submit ">Submit</button>
</form>

<script>
 var submitbtn = document.getElementById ("submit");

 Submitbtn.onclick = function (event) {
  alert ("preventdefault!");
  var event = Event | | window.event;
  Event.preventdefault (); Compatible standard browser
  window.event.returnValue = false;//compatible ie6~8
 };
</script>

These are the full contents of the two methods that use JavaScript to block form submissions, and hopefully the content of this article will help you to use JavaScript.