Existing Currency Card: <input type="checkbox" name="cardDetails" value="checkbox" onchange="showData(this)"/>
To populate values and show them in a table format from a database when clicked on a checkbox, you need to create an event listener for the checkbox. This event listener should then use an AJAX request to retrieve the data from the database, and then use JavaScript to render the data in a table format. You can use a library such as jQuery or Dojo to help simplify the process.