Question

I have a simple form and i want the submit button not to work for the conditions i give in the pattern, but if i leave it blank the submit works. how can i make the pattern not to accept it if it is blank?

<form action="test.php" method="POST">
Enter user name: 
<input type="text" name="username" pattern="[A-Za-z0-9]{1,20}">
<input type="submit" value="submit">
</form>

I thought the {1,20} is enought but it seems it’s not.

Answer 1

HTML has the required attribute to accomplish this. If you set any input to be required, modern browsers won’t let you submit the form if those fields are empty.

<input type="text" name="username" required="required" pattern="[A-Za-z0-9]{1,20}">