I wanna retrive a table in this page,and do something
however I cant getElementById directly in console before I use chrome inspecter to select it.
I cant access to the source code
so what should i do?
following screenshot show my issue
In your first screenshot your console selector is "top", in your second screenshot the selector is "zhuti(content.aspx)" - that could indicate that element is not accessible in top document (maybe it is in an iframe?)
It would be helpful if you provide html or link to source page.