auto re-sizing iframe that dynamically changing height (smaller or bigger)

Question

I know there\'s a lot of post about re-sizing iframe but all i found is this code:

Answer 1

Why not just do:

height: auto;
max-height: 1200px;

On the iframe itself within style="" or thru a css doc.

If height is set to auto, then it won't need to use the 1200px for the index.php. But when displaying the profile.php it's allowed to use a maximum of 1200px.