function resize() {
  document.all.content.style.minHeight = Math.max(document.body.clientHeight - 200, 460); 
}

function load() {
  document.all.top.style.height = '100%'; 
  document.all.bottom.style.height = '100%'; 
  document.all.header.style.height = '100%'; 
  document.all.footer.style.height = '100%'; 
  document.all.content.style.height = '100%'; 
}

//для растягивания 100% по вертикали
if (navigator.appName == 'Microsoft Internet Explorer') {
  window.onload = load;
} else {
  window.onload = resize;
  window.onresize = resize;
}