jQuery .scrollToViewPort()

yesterday i found this very useful jQuery-script on github:

https://gist.github.com/853841

jQuery.fn.scrollToViewPort = function(animTimeInterval) {
  animTimeInterval = (typeof animTimeInterval == "undefined")?"slow":animTimeInterval;
  return this.each(function(){
    $('html,body').animate({scrollTop: $(this).offset().top},animTimeInterval);
  });
}

it moves the users’ viewport to show the element that it has been called on.

I modified it somehow so that it will check now if the element is already in the viewport.
So we can avoid auto-scrolling in that case.
A offset Parameter has also been added in case we need some margin.

https://gist.github.com/1018842

jQuery.fn.scrollToViewPort = function(options) {
  var animTimeInterval = (typeof options.interval == "undefined")?"slow":animTimeInterval;
  return this.each(function(){
    var offSet = (typeof options.offset == "undefined")? $(this).offset().top : options.offset;
    if( $(this).offset().top <= $(window).scrollTop() || ( $(this).offset().top + $(this).height() ) >= ( $(window).scrollTop() + $(window).height() ) ){
      $('html,body').animate( { scrollTop: offSet }, animTimeInterval );
    }
  });
}

usage:

 $(this).scrollToViewPort( { offset : ( ( $(this).offset().top + my_custom_offset ) - $(window).height() ) } );