VS 2013 : Missing Debugging Option under Configuration Properties in the projects Property Pages

Hi,

I am trying to debug one of my web apps that has both client side code(java script) and server side code.

I am trying to implement web sockets, so hosted the App in IIS.

now when I try to debug the app, I can see the breakpoints being set properly in the .cs files.

But on the client side(in the html file with java script), it says : breakpoints cannot be hit as the symbols have not been loaded.

When I searched it online, I found the link below, which says I need to enable the mixed mode for debugging :

http://blogs.msdn.com/b/visualstudioalm/archive/2013/06/28/javascript-native-interop-debugging-in-visual-studio-2013.aspx

MY ISSUE HERE IS THAT :Debuggin Option is missing under Configuration Properties in the projects Property Pages, as shown in the pic below. Can you please let me know how this could be fixed.

ScreenShot