//语法：prev(element)
//参数：element对象
//返回：对象在当前级别中是第几个元素,从1开始
//<SPAN class=sep>2010-08-26 15:13:55</SPAN>
function prev(elem,cont) {
if(!cont){cont=1}
elem = elem.previousSibling;
if(elem){return prev(elem,(cont+1))}
return cont
}
prev($("ext-gen232"))