var jiahao=new Image();
jiahao.src="/img/+hao.gif";
var jianhao=new Image();
jianhao.src="/img/-hao.gif";
function changetreeview(id){

if($("#div_"+id).css("display")=="none"){
$("#div_"+id).show("fast");
$("#treeimg"+id).attr("src",jianhao.src);
}else{
$("#div_"+id).hide("fast");
$("#treeimg"+id).attr("src",jiahao.src);
}

}