函数

        function scroll(scrollTo, time) {
	    var scrollFrom = parseInt(document.body.scrollTop),
	        i = 0,
	        runEvery = 5;
	    
	    scrollTo = parseInt(scrollTo);
	    time /= runEvery;
	    
	    var interval = setInterval(function () {
	        i++;
	        
	        document.body.scrollTop = (scrollTo - scrollFrom) / time * i + scrollFrom;
	       
	        if (i >= time) {
	            clearInterval(interval);
	        }
	    }, runEvery);
	}    

　　

　　

function debounce(func, timeout){
    var timeId, timeout = timeout || 50;
    return function(){
        var scope = this, args = arguments;
        clearTimeout(timeId);
        timeId = setTimeout(function(){
            func.apply(scope, Array.prototype.slice.call(args));
        }, timeout);
    }
}