var loadTaxRate = {
         type:'dropdown',
         source: function(){
            var xmlhttp;
            if (window.XMLHttpRequest){// code for IE7+, Firefox, Chrome, Opera, Safari
               xmlhttp=new XMLHttpRequest();
            }else{// code for IE6, IE5
               xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
            }

            xmlhttp.onreadystatechange=function(){
               if (xmlhttp.readyState==4 && xmlhttp.status==200){
                  var data=[];

                  _.each(xmlhttp.responseText,function(x,y){
                     console.log(x, y);
                     data.push(y);
                  });
                  return {type:'dropdown',source:data};
               }
            }
            xmlhttp.open("POST","/api/xero/get/taxrates",true);
            xmlhttp.send();


         }
      };