jQuery实现自动滚动到页面顶端的方法

$(".scroll").click(function(event)
{
  //prevent the default action for the click event
  event.preventDefault();
  //get the full url - like mysitecom/index.htm#home
  var full_url = this.href;
  //split the url by # and get the anchor target 
  //name - home in mysitecom/index.htm#home
  var parts = full_url.split("#");
  var trgt = parts[1];
  //get the top offset of the target anchor
  var target_offset = $("#"+trgt).offset();
  var target_top = target_offset.top;
  //goto that anchor by setting the body scroll top to anchor top
  $('html, body').animate({scrollTop:target_top}, 500);
});?