js关卡函数，throat函数实现，定时运行函数

		function throat(callback,num){
			var timer = null;
			callback = callback || function(){};
			return function(){
				if(!timer){
					var that = this;
					var arg = arguments;
					timer = setTimeout(function(){
						callback.apply(that,arg);
						timer = null;
					},num);
				}

			}
		}

		var throats = throat(function(e){
			console.log(e.screenX,e.screenY);
		},1000);

		window.onmousemove = function(e){
			throats(e);
		};