$(function() {
function getTotalHeight() {

  // firefox is ok
  var height = document.documentElement.scrollHeight;

  // now IE 7 + Opera with "min window"
  if(document.documentElement.clientHeight > height ) {
    height  = document.documentElement.clientHeight;
  }
  // last for safari
  if(document.body.scrollHeight > height) {
    height = document.body.scrollHeight;
  }
  return height;
}
var height_total=getTotalHeight();
 $('#footer').css({ "top": height_total+"px"}); 
});