Visual studio Site.Master header bar

You don't meant which version of visual studio that you are using. However, i assume you are using latest version of Visual studio (i.e., VS2015), in this case, I guess, the webform template uses Bootstrap by default. So you can use Bootstrap menu to achieve the same like below:

 

 

You can find more on the below link:

 

http://getbootstrap.com/2.3.2/components.html