Fix horizon position but free vertical one.
for: IE 8+, Firefox, Chrome, Safari, Opera
$(elem).gpFloatX(); $(elem).gpFloatY();
The measure on top is fixed against vertical scrolling,
but it will move with window horizon scrolling.
The left one acts similarly.
The footer on bottom will scroll horizon if it has more area.
It will not scroll if its right edge is displayed.
Get more sample codes in HTML source,
and more informations in: Ginpen.com.