function moveUpNavigation() {
  documentBody             = document.getElementsByTagName('body')[0];
  documentNavigation       = document.getElementById('navigation');
  documentContent          = document.getElementById('content');
  navigationStyle          = documentNavigation.style;
  contentStyle             = documentContent.style;
  
  if(document.defaultView) {
    bodyComputedFontSize   = document.defaultView.getComputedStyle(documentBody,'').getPropertyValue('font-size') // px
    bodyComputedFontSize   = bodyComputedFontSize.replace("px","");  // remove string "px"
  } else { // For IE
    bodyComputedFontSize   = document.body.currentStyle.fontSize;  // pt
    bodyComputedFontSize   = bodyComputedFontSize.replace("pt","");  // remove string "pt"
    bodyComputedFontSize   = bodyComputedFontSize * 1.32  // convert pt->px (96dpi, 1inch = 72pt)
  }
  navigationOffsetHeight   = documentNavigation.offsetHeight;
  contentOffsetHeight      = documentContent.offsetHeight;
  
  navigationStyle.position = "relative";
  contentStyle.position    = "relative";
  navigationStyle.top      = - contentOffsetHeight / bodyComputedFontSize + "em";
  contentStyle.top         = navigationOffsetHeight / bodyComputedFontSize + "em";
}