function SwitchPic(IMGNAME, IMGPATH){
    document.images[IMGNAME].src = IMGPATH;
}
function PreloadPic(IMGNAME, IMGPATH){
    IMGNAME     = new Image();
    IMGNAME.src = IMGPATH;
}

  PreloadPic('sn4_ro_0', 'images/btn_top_over.gif');
  PreloadPic('sn4_ro_1', 'images/btn_business_over.gif');
  PreloadPic('sn4_ro_2', 'images/btn_access_over.gif');
  PreloadPic('sn4_ro_3', 'images/btn_inquiry_over.gif');
  PreloadPic('sn4_ro_4', 'images/btn_link_over.gif');
  PreloadPic('sn4_ro_5', 'images/btn_japanese_over.gif');
  PreloadPic('sn4_ro_6', 'images/btn_korea_over.gif');
  PreloadPic('sn4_ro_7', 'images/btn_english_over.gif');
  PreloadPic('sn4_ro_8', 'images/btn_chinese_over.gif');
  PreloadPic('sn4_ro_9', 'images/btn_kantai_over.gif');
  PreloadPic('sn4_ro_10', 'images/btn_hantai_over.gif');

//ポップアップ
var IE = 0,NN = 0,N6 = 0;
if(document.all) IE = true;
else if(document.layers) NN = true;
else if(document.getElementById) N6 = true;
function OnLink(Msg,mX,mY,nX,nY){
var pX = 0,pY = 0;
var sX = -10,sY = 30;
if(IE){
MyMsg = document.all(Msg).style;
MyMsg.visibility = "visible";
}
if(NN){
MyMsg = document.layers[Msg];
MyMsg.visibility = "show";
}
if(N6){
MyMsg = document.getElementById(Msg).style;
MyMsg.visibility = "visible";
}
if(IE){
pX = document.body.scrollLeft;
pY = document.body.scrollTop;
MyMsg.left = mX + pX + sX;
MyMsg.top = mY + pY + sY;
}
if(NN || N6){
MyMsg.left = nX+ sX;
MyMsg.top = nY + sY;
}
}
function OffLink(Msg){
if(IE) document.all(Msg).style.visibility = "hidden";
if(NN) document.layers[Msg].visibility = "hide";
if(N6) document.getElementById(Msg).style.visibility = "hidden";
}