function showExplanation(section) {
winOptions = "location=no,toolbar=no,directories=no,status=no,menubar=no,resizeable=no,scrollbars=no,height=300,width=250";
if (navigator.appName == "Netscape")
  winOptions += ",screenX=280,screenY=180";
else
  winOptions += ",left=280,top=180";
window.open("questionmark.php?section=" + escape(section) , "" , winOptions);
}