Remove an element from array in select menu after selecting anthor Item in anthor dropdown

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="MyCtrl">

  <form>
    Xxis
    <select ng-model="xcolumn" ng-options=" l1.columnName for l1 in list1" ng-change="getColumn(xcolumn)">
      <option value=""></option>
    </select>
    yAxis
    <select ng-model="xcolumn" ng-options=" l2.columnName for l2 in list2" ng-change="getColumn()">
      <option value=""></option>
    </select>

  </form>
</div>

JavaScript

var myApp = angular.module('myApp', []);

//myApp.directive('myDirective', function() {});
//myApp.factory('myService', function() {});

myApp.controller('MyCtrl', function($scope) {
  $scope.list1 = [{
    "columnName": "part1",
    value: "obj1"
  }, {
    "columnName": "part2",
    value: "obj2"
  }, {
    "columnName": "part3",
    value: "obj3"
  }, {
    "columnName": "part4",
    value: "obj4"
  }, {
    "columnName": "part5",
    value: "obj5"
  }]


  $scope.list2 = [{
    "columnName": "part1",
    value: "obj1"
  }, {
    "columnName": "part2",
    value: "obj2"
  }, {
    "columnName": "part3",
    value: "obj3"
  }, {
    "columnName": "part4",
    value: "obj4"
  }, {
    "columnName": "part5",
    value: "obj5"
  }]


  $scope.getColumn = function(colum) {
    // console.log(index, 'index of column')

    $scope.indexOfcolum = $scope.list2.indexOf(colum);
    $scope.removecolum = $scope.list2.splice($scope.indexOfcolum, 1)
    console.log($scope.indexOfcolum, 'colum index', $scope.removecolum)
  }
});