/* 参数：绑定块类名，延迟时间，动画模式(1为只运行一次，默认为无限)，自定义动画类名(默认为向上渐隐渐现) */
function fadeanim(_node,time,num,animclass){
    $("body").append('<div class="fixed_top"></div>');
    var topvalue = $(".fixed_top").offset().top;
    var btop = $(_node).offset().top - $(window).height();
    var timeb = time > 2 ? time : 0;
    var numb = time < 2 ? time : 0;    
    numb = num ? num : numb;
    var animclassb = "animtop";    
    if(typeof animclass == "string"){
      animclassb = animclass;
    }else if(typeof time == "string"){
      animclassb = time;
    }else if(typeof num == "string"){
      animclassb = num;
    }

    if (client.browser.ie != 7) { 
        function animfun(){
          $(_node).addclass("animinto");
          btop = $(_node).offset().top - $(window).height() + 100;    
              if(topvalue > btop){
                settimeout(function(){
                  $(_node).addclass(animclassb);              
                },timeb)                
              }else if(numb != 1){
                $(_node).removeclass(animclassb);
              }
        }       

        animfun();
        $(window).scroll(function(){
          topvalue = $(".fixed_top").offset().top;
          animfun(_node);
        })
    }
}

/*
  调用
  fadeanim(".class",400,1,"animclass");
*/