height=100% do not work

the code below are all height=100%, it works fine in chrome but it displayes very strange in firefox and ie开发者_运维百科7!it is not exactly the 100% height.anyone knows? thanks a million.

<iframe src ="demoFramesetLeftFrame.jsp" name="treeframe" id="treeframe" 
        width=200px height=100% frameborder=0>
</iframe>
 <iframe src="middle.html" name="middle" id="middle"
        width=200px height=100% frameborder=0>
</iframe>
<iframe src="test.html" name="basefrm" id="basefrm"
        width=200px height=100% frameborder=0>
</iframe>

You may need a container div, with a min-height property. Writing 100% height in HTML for some reason is one of the hardest things to do.

Here are some tutorials on how 100% height can be achieved

http://www.dave-woods.co.uk/?p=144

http://www.webmasterworld.com/forum83/200.htm