function info_on(el,inf) {
  var a=el.src;
  el.src=a.substring(0,a.indexOf('.gif')-1)+'2.gif';
  document.getElementById(inf).style.visibility="visible";
}

function info_off(el,inf) {
  var a=el.src;
  el.src=a.substring(0,a.indexOf('.gif')-1)+'1.gif';
  document.getElementById(inf).style.visibility="hidden";
}

function enable(s1,e1,s2,e2,tf,str) {
  var colo=(tf?"#000000":"#999999");
  for(var i=s1; i<e1; i++)
    document.getElementsByName(str)[0][i].disabled=(!tf);
  for(i=s2; i<e2; i++)
    document.getElementsByName("filtag")[i].style.color=colo;
}