How to add new empty row on dropdown change using angular

by using below code am adding new row on dropdown change,

if select option 'madhu' in dropdown ,adding new row with same selected madhu .if i select any dropdown madhu,all values are changing to madhu

how to fix this, iwant to add new empty row on dropdown change

select Customer

Select Account

js

$scope.rvm = [{}];

$scope.GetAccountBalance = function (index) {

var getAccountBalance = ReceiptsService.GetAccountBalance($scope.customer.ID);

var id = $scope.customer.ID;

alert(id);

if ($scope.rvm.length == (index + 1)) {

$scope.rvm.push({

});

}