if(navigator.appVersion.charAt(0) >= 3) {
var img = new Array();

img[1] = new Image();  img[1].src="/img/top.jpg"; 
img[2] = new Image();  img[2].src="/img/top_on.jpg"; 
img[3] = new Image();  img[3].src="/img/about.jpg"; 
img[4] = new Image();  img[4].src="/img/about_on.jpg"; 
img[5] = new Image();  img[5].src="/img/construction.jpg"; 
img[6] = new Image();  img[6].src="/img/construction_on.jpg"; 
img[7] = new Image();  img[7].src="/img/service.jpg"; 
img[8] = new Image();  img[8].src="/img/service_on.jpg"; 
img[9] = new Image();  img[9].src="/img/result.jpg"; 
img[10] = new Image();  img[10].src="/img/result_on.jpg"; 
img[11] = new Image();  img[11].src="/img/voice.jpg"; 
img[12] = new Image();  img[12].src="/img/voice_on.jpg"; 


}
function change_image(nam,num) {
  if(navigator.appVersion.charAt(0) >= 3) {
    document.images[nam].src = img[num].src;
  }
}