var objCount = 0;
function preload(name, first, second) { 
if (browserOK) { 
pics[objCount] = new Array(5);
pics[objCount][0] = new Image();
pics[objCount][0].src = first;
pics[objCount][1] = new Image();
pics[objCount][1].src = second;
pics[objCount][2] = name;
objCount++;
}
}
function on(name){
if (browserOK) {
for (i = 0; i < objCount; i++) {
if (document.images[pics[i][2]] != null)
if (name != pics[i][2]) { 
document.images[pics[i][2]].src = pics[i][0].src;
} else {
document.images[pics[i][2]].src = pics[i][1].src;
}
}
}
}

function off(){
if (browserOK) {
for (i = 0; i < objCount; i++) {
if (document.images[pics[i][2]] != null) 
document.images[pics[i][2]].src = pics[i][0].src;
}
}
}
preload("image1", "images/up_home.jpg", "images/over_home.jpg");
preload("image2", "images/up_about.jpg", "images/over_about.jpg");
preload("image3", "images/up_product.jpg", "images/over_product.jpg");
preload("image4", "images/up_cutting.jpg", "images/over_cutting.jpg");
preload("image5", "images/up_plant.jpg", "images/over_plant.jpg");
preload("image6", "images/up_contact.jpg", "images/over_contact.jpg");
//preload("image7", "images/btn_support_staff_1-2.jpg", "images/btn_support_staff_2-2.jpg");
//preload("image8", "images/btn_employment_1-2.jpg", "images/btn_employment_2-2.jpg");
//preload("image9", "images/btn_contact_1-2.jpg", "images/btn_contact_2-2.jpg");
//preload("image10", "images/btn_faqs_1-2.jpg", "images/btn_faqs_2-2.jpg");