JavaScript Modal

1. preventDefault() Event Method

The preventDefault() method cancels the event if it is cancelable, meaning that the default action that belongs to the event will not occur.

For example, this can be useful when:

• Clicking on a “Submit” button, prevent it from submitting a form
• Clicking on a link, prevent the link from following the URL

Note: Not all events are cancelable. Use the cancelable property to find out if an event is cancelable.

Note: The preventDefault() method does not prevent further propagation of an event through the DOM. Use the stopPropagation() method to handle this.

2. Submitting forms and uploading files

https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/Using_XMLHttpRequest

3. Ajax

https://developer.mozilla.org/en-US/docs/Web/Guide/AJAX/Getting_Started