function toggleLayer(whichLayer, dImage)
{

if (document.getElementById)
{
// this is the way the standards work
var style2 = document.getElementById(whichLayer).style;
style2.display = style2.display? "":"block";
}
else if (document.all)
{
// for old MS IE versions
var style2 = document.all[whichLayer].style;
style2.display = style2.display? "":"block";
}
else if (document.layers)
{
// for NN4 if you really must!
var style2 = document.layers[whichLayer].style;
style2.display = style2.display? "":"block";
}

}