image to overlap existing page..... div tag?

hello,

I have a long page . When viewing the page I am trying to have an image completely over lap what already exists on the page without editing any of the already existing HTML......

I am trying to have a smaller image ( jpg ) towards the middle-top of the page and another one all the way in the bottom left corner (about 2 1/2 page lengths down).....

this is what I have so far, but the second image that belongs in the bottom left corner is nowhere near the bottome left corner....

<div style="position:absolute; top:38%; left:22.5%;">
<IMG SRC="MYPIC.JPG">
</div>
<div style="position:absolute; top:100%; left:100%;">
<IMG SRC="MYOTHERPIC.JPG">
</div>

What is the best way to get these images precisely aligned without editing the existing HTML at all... Thanks in advance everyone :p

have you tried this?
<img style="position: absolute; bottom: 0; right: 0;" src="image.gif" alt="whatever" />