JS script selects elements in an IFRAME

Encounter a small problem, need to use the original JS processing the elements of the page, the past a document.getElementById on the live selection of elements, this time is not working.

Look closely at the code to find an IFRAME tag outside of the selected element

<iframe id= "iframe_id" >      ... </iframe>

Baidu know, at this time the contents of the IFRAME package is equivalent to another page, in the current page of the document has not been taken, you need to obtain this IFRAME element, and then to further get to Select the element:

Compatible with each browser:
document.getElementById (' iframe_id '). Contentwindow. document.getElementById (' dest_id ')

>ie8 Browser, Firefox:document.getElementById (' iframe_id '). contentdocument. getElementById (' dest_id ')

Successfully selected to element at this point ... Don't spit on Me, I met the IFRAME page really few ...

JS script selects elements in an IFRAME