function showPreview(imagePath,ctitle){
document.getElementById('resimg').innerHTML ="";
document.getElementById('sernav').innerHTML ="";
document.getElementById('sernav').innerHTML =ctitle;
var a = document.createElement("a");
a.setAttribute("href",imagePath);
a.setAttribute("title","点击查看大图");
a.setAttribute('target', '_blank'); 	
document.getElementById('resimg').appendChild(a);	
var img = document.createElement("img");
img.setAttribute("src",imagePath);
a.appendChild(img);	
//document.getElementById('fir').style ="display:none";
}