if (document.images) {

playon = new Image(87, 47);
playon.src = "picts/calculateon.png"

playoff = new Image(87, 47);
playoff.src = "picts/calculateoff.png"

play1on = new Image(87, 47);
play1on.src = "picts/downloadon.png"

play1off = new Image(87, 47);
play1off.src = "picts/downloadoff.png"

play2on = new Image(87, 47);
play2on.src = "picts/calculateon.png"

play2off = new Image(87, 47);
play2off.src = "picts/calculateoff.png"

play3on = new Image(87, 47);
play3on.src = "picts/searchon.png"

play3off = new Image(87, 47);
play3off.src = "picts/searchoff.png"

play4on = new Image(87, 47);
play4on.src = "picts/contacton.png"

play4off = new Image(87, 47);
play4off.src = "picts/contactoff.png"


}

function img_act(imgName) {
if (document.images) {
imgOn = eval(imgName + "on.src");
document [imgName].src = imgOn;
}
}

function img_inact(imgName) {
if (document.images) {
imgOff = eval(imgName + "off.src");
document [imgName].src = imgOff;
}
}