Its a three column mixed layout design.
Combination is Fluid-Fixed-Fixed.-----I shall describe the basic formula here.With this you can design your own mixed layout-
So left column is liquid here.
For left column the basic is {margin-right: (middle column width+right column width) px}
thats all.Now to add style its up to you.But the liqudity is complete here.
For middle column-- {margin-left:-(middle column width+right column width) px}
For right column- {margin-left:-right column width px;}
Thats all,thats the basic formula to build any type of liquid-fixed lay out.