js 根据xpath 得到element

function _x(STR_XPATH) { 

 var xresult = document.evaluate(STR_XPATH, document, null, XPathResult.ANY_TYPE, null); var xnodes = [];

 var xres; 

 while (xres = xresult.iterateNext()) { xnodes.push(xres); } 

 return xnodes; 

}