var WeekCount = 9;

function showDescription (n) {
  for (i=1; i<=WeekCount; i++) {
    document.getElementById ("description" + i).style.display = (i == n ? "block" : "none");
    document.getElementById ("pointer"     + i).style.display = (i == n ? "block" : "none");
  }
}


function mouseOverImg (img) {
  img.src = img.src.replace (".gif", "-hover.gif");
}


function mouseOutImg (img) {
  img.src = img.src.replace ("-hover.gif", ".gif");
}