Buon giorno from 11 degrees C no Sun Wetherby UK...

Working on this tutorial http://www.maxdesign.com.au/articles...uts/two-fixed/ I'm wanting to make sure i understand what this bit of code does:

#layout-two-fixed #content-container{

background: url("layout-two-fixed-background.gif") repeat-y scroll 100% 0 #FFFFFF;
float: left;
width: 900px;

I get this is the bit of code that adds the grey repearting gif befind the right hand side column but what i dont get is this bit 100% O - is this like x y co-ordinates or something.

Thanks in advance,