function swImg(iName, str) {
  document.images[iName].src = str;
}

function preImg() { 
  data = new Array(
  '../navi/03o.gif','../navi/06o.gif','../navi/08o.gif','../navi/10o.gif','../navi/12o.gif',
  '../navi/14o.gif','../navi/16o.gif','../navi/18o.gif','../navi/20o.gif','../navi/22o.gif');
  prImg = new Array();
  for (i=0;i<data.length;i++)
  {
  	prImg[i] = new Image();
	prImg[i].src = data[i];
  }
}