title: Scroll to specific div from another page minus X distance
body: <p>I'm using the following script to perform the action described in my title.</p>
  
  <pre><code>    &lt;script type="text/javascript"&gt;
                var jump=function(e)
        {
           if (e){
               e.preventDefault();
               var target = $(this).attr("href");
           }else{
               var target = location.hash;
           }
  
           $('html,body').animate(
           {
               scrollTop: $(target).offset().top
           },1000,function()
           {
               location.hash = target;
           });
  
        }
  
        $('html, body').hide();
  
        $(document).ready(function()
        {
            $('a[href^=#]').bind("click", jump);
  
            if (location.hash){
                setTimeout(function(){
                    $('html, body').scrollTop(0).show();
                    jump();
                }, 0);
            }else{
                $('html, body').show();
            }
        });
        &lt;/script&gt; 
  </code></pre>
  
  <p>It works perfectly fine. However I have a fixed header which covers up the div once it's scrolled to. I'd like to minus 80px from the desired scroll target. How can I modify the code to do this?</p>
  
  <p>Here's a live version. </p>
  
  <p>robertkoh.net/Electrotemp/index.html </p>
  
  <p>Click on 'ducted vacuum systems'. It takes you to the products and services page and scrolls to the appropriate section. As you can see the fixed header covers part of it. </p>