function reset()
{
  document.all.grid1hover.style.visibility = "hidden";
  document.all.grid3hover.style.visibility = "hidden";
  document.all.grid4hover.style.visibility = "hidden";
  document.all.grid6hover.style.visibility = "hidden";
  document.all.grid9hover.style.visibility = "hidden";
  document.all.grid10hover.style.visibility = "hidden";
  document.all.grid11hover.style.visibility = "hidden";
  document.all.grid12hover.style.visibility = "hidden";
  document.all.grid15hover.style.visibility = "hidden";

}

function grid1()
{
  document.all.grid1hover.style.visibility = "visible";
}

function grid3()
{
  document.all.grid3hover.style.visibility = "visible";
}

function grid4()
{
  document.all.grid4hover.style.visibility = "visible";
}

function grid6()
{
  document.all.grid6hover.style.visibility = "visible";
}

function grid9()
{
  document.all.grid9hover.style.visibility = "visible";
}

function grid10()
{
  document.all.grid10hover.style.visibility = "visible";
}

function grid11()
{
  document.all.grid11hover.style.visibility = "visible";
}

function grid12()
{
  document.all.grid12hover.style.visibility = "visible";
}

function grid15()
{
  document.all.grid15hover.style.visibility = "visible";
}