IE6 height issue

Question

Hello gentlemen,

I am experiencing a very weird problem in IE6. I have a mask div that sits behind a message div, however, this mask div, needs to extend with the height of the parent container. IE 7 and IE8 are behaving nicely. I get the expected result. However, IE6 only displays the mask div on top of the div that should sit infront of it.

Can someone tell me how can I make the div expand to 100% of the parent div. NOTE: parent div is set with height: auto.

LAYOUT is

<div class="container">
  <div class="mask"></div>
  <div class="content"></div>
  <div class="content"></div>
</div>

Expected result is that the mask div expands the same size as the parent div which in this case it is the container div.

Thanks for the help in advanced.

-E