Как вы можете помочь мне решить мою проблему в этом коде

//I need to sort my json object data
//this javaScript code is working but when i try to adding function mysort isn't work:
var data=[{"name":2013,"DATA":[{"x":44,"y":637}]},
{'name':2015,'DATA':[{'x':44,'y':'477'}]},
{'name':2013,'DATA':[{'x':44,'y':'467'}]},
{'name':2016,'DATA':[{'x':44,'y':'67'}]},
{'name':2013,'DATA':[{'x':44,'y':'77'}]}];

$(function(){
$("#sort").hide();
loaddata_unsort();
$("#button").click(function(){
  loaddata_sort();
  $("#sort").show();
});
//end click***********************************
function loaddata_unsort(){
  var html="";
  for (var i = 0; i < 5; i++) {
  html+="";
};
$("#unsort").append(html);
};
//end loaddata_unsort********************************
function loaddata_sort(){
  
  var datasort=data.sort(mysort);//this line is problem
  var html="<table><tbody><tr><th>year</th><th>Xvalue</th><th>Yvalue</th></tr><tr><td>"+data[i].name+"</td><td>"+data[i].DATA[0].x+"</td><td>"+data[i].DATA[0].y+"</td></tr></tbody></table>";
  for (var i = 0; i < 5; i++) {
  html+="";
 }
$("#sort").append(html);
};
//end function loaddata_sort************************************
});//end  jquery

function mysort(a,b){
   if(a.name!=null && a.name!undefined && b.name!=null && b.name!=undefined)
   {
     var first=a.name.toString.toLowerCase();
     var secend=b.name.toString.toLowerCase();
     return secend-first;
 };
 };<table><tbody><tr><th>year</th><th>Xvalue</th><th>Yvalue</th></tr><tr><td>"+datasort[i].name+"</td><td>"+datasort[i].DATA[0].x+"</td><td>"+datasort[i].DATA[0].y+"</td></tr></tbody></table>