if(navigator.appVersion.charAt(0) >= 3) {
var img = new Array();
img[1] = new Image();  img[1].src="images/menu_b/work.jpg"; 
img[2] = new Image();  img[2].src="images/menu/work.jpg"; 
img[3] = new Image();  img[3].src="images/menu_b/about.jpg"; 
img[4] = new Image();  img[4].src="images/menu/about.jpg"; 
img[5] = new Image();  img[5].src="images/menu_b/recruit.jpg"; 
img[6] = new Image();  img[6].src="images/menu/recruit.jpg"; 
img[7] = new Image();  img[7].src="images/menu_b/access.jpg"; 
img[8] = new Image();  img[8].src="images/menu/access.jpg"; 
img[9] = new Image();  img[9].src="images/menu_b/contact.jpg"; 
img[10] = new Image();  img[10].src="images/menu/contact.jpg";
img[11] = new Image();  img[11].src="images/menu_b/link.jpg"; 
img[12] = new Image();  img[12].src="images/menu/link.jpg"; 
img[13] = new Image();  img[13].src="images/top_side_b.gif"; 
img[14] = new Image();  img[14].src="images/top_side_a.gif"; 
img[15] = new Image();  img[15].src="images/btn_b/btn_01.gif"; 
img[16] = new Image();  img[16].src="images/btn/btn_01.gif";
img[17] = new Image();  img[17].src="images/btn_b/btn_02.gif"; 
img[18] = new Image();  img[18].src="images/btn/btn_02.gif";
img[19] = new Image();  img[19].src="images/btn_b/btn_03.gif"; 
img[20] = new Image();  img[20].src="images/btn/btn_03.gif";
img[21] = new Image();  img[21].src="images/btn_b/btn_04.gif"; 
img[22] = new Image();  img[22].src="images/btn/btn_04.gif";
img[23] = new Image();  img[23].src="images/btn_b/btn_05.gif"; 
img[24] = new Image();  img[24].src="images/btn/btn_05.gif";
img[25] = new Image();  img[25].src="images/btn_b/btn_06.gif"; 
img[26] = new Image();  img[26].src="images/btn/btn_06.gif";
img[27] = new Image();  img[27].src="images/btn_b/btn_07.gif"; 
img[28] = new Image();  img[28].src="images/btn/btn_07.gif";
}
function change_image(nam,num) {
  if(navigator.appVersion.charAt(0) >= 3) {
    document.images[nam].src = img[num].src;
  }
}