Get parent tag_Basics

function obj_event_onsomething(e){
var e=window. event?window.event:e;
var srcEle=e.srcElement?e.srcElement:e.target;
var theObjectYouWant=srcEle.parentNode;
}

o .previousSibling.href || o.previousSibling.previousSibling.href
The former expression is used under IE, and the latter one is used under FireFox.
Because under IE, XMLDom does not have the preserveWhiteSpace attribute, that is: put the blank space It is also treated as a node, and IE defaults to false, that is, the blank is not regarded as a node.

XMLDom is mentioned here, which seems to be irrelevant to what is mentioned above, but under FireFox, previousSibling is blank. Unless there is no space of any kind between the two HTML tags.