btn = new Array();
btnon = new Array();
disp = new Array();

if (document.all)
 for (var i=0; i<7; i++)
  {
  btn[i] = new Image();
  btnon[i] = new Image();
  disp[i] = new Image();
  btn[i].src = "./i/nv-btn-"+(i+1)+".gif";
  btnon[i].src = "./i/nv-btn-"+(i+1)+"s.gif";
  disp[i].src = "./i/screen-"+(i+1)+".gif";
  }

dtmp = new Image();
dtmp.src = "";

function rollON(n)
{
 document.images["display"].src = (document.all) ? disp[n-1].src : "./i/screen-"+n+".gif";
 dtmp.src = document.images["btn"+n].src;
}

function rollOFF(n)
{
// document.images["display"].src = (document.all) ? disp0.src : "./i/screen-0.gif";
 document.images["display"].src = disp0.src;
// document.images["btn"+n].src = dtmp.src;
}

function rollMD(n)
{
 document.images["btn"+n].src = (document.all) ? btnon[n-1].src : "./i/nv-btn-"+n+"s.gif";
}

function rollMU(n)
{
 document.images["btn"+n].src = (document.all) ? btn[n-1].src : "./i/nv-btn-"+n+".gif";
}