chart.js (intermediate value).Line is not a

Question

$(function(){

var ctx = $("#chatbox").get(0).getContext("2d");
window.myNewChart = new Chart(ctx).Line(data);;new Chart(ctx).Line(data);
var data = {     labels : ["January","February","March","April","May","June","July"],     datasets : [
         {             fillColor : "rgba(220,220,220,0.5)",             
         strokeColor : "rgba(220,220,220,1)",             
         pointColor : "rgba(220,220,220,1)",             pointStrokeColor : "#fff",             
         data : [65,59,90,81,56,55,40]
         },
         {             fillColor : "rgba(151,187,205,0.5)",             
         strokeColor : "rgba(151,187,205,1)",            
          pointColor : "rgba(151,187,205,1)",             pointStrokeColor : "#fff",             
          data : [28,48,40,19,96,27,100]
         }
     ]

}
});

新手求助...刚学这个..为什么会出现 (intermediate value).Line is not a function(…)
引入的文件是Chart.js