Workarounds for nested HTML forms?

I have been driving myself silly trying to solve this. :crazy:

I have a simple form with (basically) three fields, title, image_url, and, information, all three text.

<form action="index.php?action=save" method="post">
   <input type="text" name="title" value="<php echo $title; ?>" />
   <input type="text" name="image_url" value="<php echo $image_url; ?>" />
   <input type="text" name="information" value="<php echo $information; ?>" />

   <input type="submit" value="Save" />
</form>

Simple enough.

Now, a feature was added that allows users to add images from their gallery. They are redirected to another page, and when they have chosen an image (or hit cancel) they are returned back to the original edit page. I have more code that I will exclude that saves the three fields in case the user hasn’t saved before clicking the “Choose from my gallery” button.

<form action="index.php?action=save" method="post">
   <input type="text" name="title" value="<php echo $title; ?>" />
   <input type="text" name="image_url" value="<php echo $image_url; ?>" />
   <form action="index.php?action=choose_image" method="post">
      <!-- insert a whole slew of REQUIRED "hidden" fields here -->
      <input type="submit" value="Choose from my gallery" />
   </form>

   <input type="text" name="information" value="<php echo $information; ?>" />

   <input type="submit" value="Save" />
</form>

HTML does not like this at all, however,** it is very important that I am able to nest that second form inside of the first.

There is NO WAY I can go to the “choose from gallery” page without all those extra hidden fields**, so a simple link won’t work, and it’s too much info to include with GET.

Are there any workarounds anyone can think of? I have exhausted all my last hope…

I would prefer to stick to HTML if possible and avoid JavaScript, as very little of the rest of the site is in JavaScript, however, if it really becomes necessary, I guess I will be forced to use it.