//导航地图显示
function common() {
if (document.all && document.getElementById) {
navRoot = document.getElementById("nav");
for (i=0; i < navRoot.childNodes.length; i++) {
node = navRoot.childNodes[i];
if (node.nodeName=="LI") {
node.onmouseover=function() {
this.className+=" over";
  }
  node.onmouseout=function() {
  this.className=this.className.replace(" over", "");
   }
   }
  }
 }
//限制图片大小
for (j=0;j<document.images.length;j++)
{
document.images[j].width=(document.images[j].width>550)?"550":document.images[j].width;
}
}
window.onload=common;