how to expand all tree structure at once in webpage

Hi! I am a Chinese from Malaysia, I have been use google and yahoo to search for css and html answer few weeks already , but because of i am study mechanical engineering , have no coding basic at all , so until now i still cannot solve my problem.

Put multiple show/hide divs within another show/hide div in Javascript

I'm trying to create a code that will allow me to put a show/hide div inside of another show/hide div but when I click the second div (the show/hide div located inside of the other show/hide dive) it makes the other copied divs in the other colums collapse also and when I click the button the buttons that drop down from the first div it also makes everything else collapse. How do I make it so that it each column drop down individually when clicked and how do I make it so that when the buttons are clicked in the second div it makes another set of div buttons drop down? I'm new so go easy.

Problem with Hide/Show column in css

I have a Table in my application. Table id is "joining_resumes_table". In that table i have 4 columns like this below

                                   <table>  
                                    <tr>
                                   <th> Name </th>
                                   <th> Requirement </th>
                                   <th> Joining Date </th>
                                   <th class ="hidden_by_default"> Accept Date </th>
                                    </tr>
                                    <tr>

Syndicate content