jquery - How can I add/remove a class to an element when URL contains a specific string?

I have some tabs:

  

    
Home
    
content
  

  
  

    
home
    
content

  

And I would like to add a class to the tab, when my URL contains the string ?dir.

So for example: if my URL is www.mypage.com/?dir=something then #contenttab should be active. And if the URL is for example only
www.mypage.com then #contenttab should not be active but #hometabshould be active.

My script is not working. #contenttabis always active and #hometab is never active.

Answer

Try checking with this :

if ( url.indexOf( '?dir' ) !== -1 ) { ... }

Or try with :

var url = location.search; // or location.href;

if ( url.indexOf( '?dir' ) !== -1 ) { ... }