image1 = new Image();
image1.src = "images/click_konferans.gif";
image1on = new Image();
image1on.src = "images/click_konferans_over.gif";

image2 = new Image();
image2.src = "images/click_fuar.gif";
image2on = new Image();
image2on.src = "images/click_fuar_over.gif";

image3 = new Image();
image3.src = "images/click_conference.gif";
image3on = new Image();
image3on.src = "images/click_conference_over.gif";

image4 = new Image();
image4.src = "images/click_expo.gif";
image4on = new Image();
image4on.src = "images/click_expo_over.gif";

imageStay = ""

function imageon(name){
        if (imageStay != name){
                document[name].src = eval(name + "on.src");
        }
}

function imageoff(name){
        if (imageStay != name){
                document[name].src = eval(name + ".src");
        }
}

function on(name){
        imageon(name);
}

function off(name){
        imageoff(name);
}

function stay(name){
        document[name].src = eval(name + "stay.src");
        if (imageStay != name){
                if (imageStay != ""){
                        document[imageStay].src = eval(imageStay + ".src");
                }
        }
        imageStay = name
}