Code for validating login textbox in
Where possible, require user confirmation for irreversible actions, such as permanent deletion of data.
Examples include: These tutorials provide best-practice guidance on implementing accessibility in different situations.
HTML5 input types are displayed as simple input fields in older web browsers that do not support these HTML5 features.
The example below shows these HTML5 input types in action.
If your web browser supports HTML5, it will not allow you to submit the form without entering text into the input field.
Instead, it will display a message that is generated by the web browser itself.
In the example below, the element specifies a particular format that matches car license plate (registration) numbers in Germany.
In some situations, such as validating custom controls or supporting legacy browsers, additional scripting may be necessary to validate user input.
Custom validation needs to notify users in an accessible way as described in the User Notifications part of this tutorial.
Input errors, such as an incorrect email address, will be indicated using the web browser dialogs as in the previous example.
attribute allows the use of regular expressions to specify custom formats for the input.