Creates a smooth scrolling. Based off http://tinyurl.com/smoothscrollingjs. Added features: Use the smooth scroll for only specific anchor tags, and keeps the #anchor name for future linking purposes.

smoothscroll

var jump=function(e){
   //prevent the "normal" behaviour which would be a "hard" jump
   e.preventDefault();
   //Get the target
   var target = $(this).attr("href");
   //perform animated scrolling
   if(target =='#home' || target=='#about'|| target=='#portfolio' || target=='#contact'){
		$('html,body').animate(
		{
			//get top-position of target-element and set it as scroll target
			scrollTop: $(target).offset().top
			//scrolldelay: 2 seconds
		},1000,function()
		{
			   //attach the hash (#jumptarget) to the pageurl
			   location.hash = target;
		});
	}else{
	}
}
$(document).ready(function()
{
       $('a[href*=#]').bind("click", jump);
       return false;
});