function MenuSlide(){
	jQuery("#sideNavi").stop();
	var offset = $('contents').positionedOffset();
	var yofset = getWinYOffset();
	if(yofset > offset[1]){
		//document.getElementById("sideNavi").style.top=(yofset - offset[1] + 10)+"px";
		jQuery("#sideNavi").animate({ 
			top: (yofset - offset[1] + 10) + "px"
		}, 500 );
	}else{
		//document.getElementById("sideNavi").style.top="0px";
		jQuery("#sideNavi").animate({ 
			top: 0 + "px"
		}, 500 );
	}
}
function getWinYOffset(){
  if(window.scrollY) return window.scrollY; // Mozilla
  if(window.pageYOffset) return window.pageYOffset; // Opera, NN4
  if(document.documentElement && document.documentElement.scrollTop){ // 以下 IE
   return document.documentElement.scrollTop;
  }
  else if(document.body && document.body.scrollTop){
   return document.body.scrollTop;
  }
  return 0;
}

//onscroll = Menu;