Image1 = new Image()
Image1.src = "images/region.jpg"

Image2 = new Image()
Image2.src = "images/region_Laos.jpg"

Image3 = new Image()
Image3.src = "images/region_Korea.jpg"

function Korea() {
document.region.src = Image3.src; return true;
}

function Laos() {
document.region.src = Image2.src; return true;
}

function original() {
document.region.src = Image1.src; return true; 
}