How do you adjust the height of a child page in an iframe?

There are several ways to adjust the height of the subpage:

1. Set the height of child pages using CSS styles.
2. Set the height of iframe with id “myiframe” to 500px in the style sheet, and the source of the iframe should be the address of the child page.
3. Dynamically set the height of a child page using JavaScript.
4. 
   
5. Set the height of a child page using jQuery.
6. Include the jQuery library by adding the following code snippet to your HTML file:
   “`html
   
   “`

   Then, add the following JavaScript code within `
   ```

   Lastly, include an `
   ```

Please replace the "subpage address" in the code above with the actual subpage address.