How do I reverse a checkbox state to make it unchecked (AngularJS)?

I basically want that when the user clicks on a checkbox, their decision is immediately reversed and the checkbox is unchecked. The code below is not working. I tried other variations like value = !value instead of value = false and tried initializing another controller variable to be equal to the checkbox variable and changing the other controller variable. None of this works; basically, I cannot set the checkbox state unless the application is first being initialized.

HTML code:

<input type="checkbox" ng-model="avariabledefinedincontroller" ng-click="changemystate(avariabledefinedincontroller)">

Controller code:

$scope.avariabledefinedincontroller = false;


$scope.changemystate = function(value){
  if (value == true) {
    value = false;

 }

 else {
   value = value;
 }

};