Don't submit form after calling Javascript function

Question

I have this problem:

my HTML code:

<form name="addUser" method="post" action="../src/process_register.php">
 ....
 <button type="submit" onClick="formhash_register(this.form);">Submit</button>
</form>

my JavaScript code:

function formhash_register(form) 
{
var username = form.inputUsername.value;
if(username == "")
 return false;
 else
 form.submit();
}

Although my function returns false, you will go to another page, and thats not what I wanted. Is there way to cancel submit process when the submit button is pressed ?

Answer 1

Try this:

 <button type="submit" 
 onClick="return formhash_register(this.form);">Submit</button>

• defrost: Just have in mind that javascript can be disabled, so preventing submission is not 100% bulletproof. Always validate user input on server too.

Answer 2

Change type to "button" which shouldn't automatically submit this form.

<button type="submit" onClick="formhash_register(this.form);">Submit</button>