div are block elements, so by default they go on seperate lines. to put a
div side by side must be done with a css position command. in general to use
positioning, you need to set absolute heights and widths to divs, so you can
position them correctly. often you want client script to calc offsets based
on screen size.
try;
<html>
<body>
<div
style="background-color:green;position:absolute;left:10;top:10;width:400;height:100;">
top
</div>
<div
style="background-color:red;position:absolute;left:10;top:610;width:400;height:100;">
bottom
</div>
<div>
<div
style="background-color:blue;position:absolute;left:10;top:110;width:100;height:500;">
left
</div>
<div
style="background-color:yellow;position:absolute;left:110;top:110;width:300;height:500;">
right
</div>
</body>
</html>