Single page hash links scrolling with offset value jQuery

jQuery('.menu a[href*=#]:not([href=#])').each(function(){
    
    $('a[href*=#]:not([href=#])').click(function() 
  {
    if (location.pathname.replace(/^\//,'') == this.pathname.replace(/^\//,'') 
        || location.hostname == this.hostname) 
        {
          
          var target = $(this.hash);
          var menu_href_val = $(this).attr('href');
          if(menu_href_val!== '#about-us'){
            headerHeight = $("#masthead").innerHeight(); // Get fixed header height
            }
            else {
                 headerHeight = $("#masthead").innerHeight()+120; // Get fixed header height
            }
          target = target.length ? target : $('[name=' + this.hash.slice(1) +']');
                  
          if (target.length) 
          {
            $('html,body').animate({
              scrollTop: target.offset().top - headerHeight
            }, 500);
            return false;
          }
        }

        });
    });