Twitter Bootstrap tabs not working: when I click on them nothing happens

Question

I am trying to implement Twitter Bootstrap tabs in the following code, but it does not seem to work. The tabs get displayed, but when I click on them nothing happens. Below

Answer 1

I tried the codes from bootstrap's document as follows:

  
  
  



    
 
      

        
Section 1
        
Section 2
      
      

        

          
I'm in Section 1.
        
        

          
Howdy, I'm in Section 2.
        
      
    
 

and it works. But when I switch these two