AngularJS TypeError: $sessionStorage.SessionMessage.replace is not a function at Object

Getting an error on the console after session reset :

angular.js:11594 TypeError: $sessionStorage.SessionMessage.replace is not a function at Object.<anonymous> (receipt.js:12) at Object.e [as invoke] (angular.js:4182) at z.instance (angular.js:8441) at angular.js:7693 at s (angular.js:331) at v (angular.js:7692) at g (angular.js:7075) at angular.js:6954 at angular.js:1451 at l.$eval (angular.js:14384)

index.js :

//javascript code to disable the browser back button after getting into the receipt page
function preventBack() { window.history.forward(); }
setTimeout("preventBack()", 0);
window.onunload = function () { null };

var app = angular.module('homeapp', ['ngStorage']);
app.controller("HomeController", function ($scope, $sessionStorage, $http) {
    $scope.btntext = "Login";
    $scope.login = function () {
        $scope.mydata = {};
        $sessionStorage.SessionMessage = {};
        $http.get("http://stagingserver:85/EBSApi/api/Users/GetAllUsers?username=" + $scope.user.username + "&password=" + $scope.user.password + "")
        .then(function (response) {
            //debugger;
            $scope.mydata = JSON.parse(response.data);
            $sessionStorage.SessionMessage = {};
            angular.forEach($scope.mydata, function (item) {
                //debugger;
                $scope.stat = "false";
                angular.forEach($scope.mydata, function (item) {
                    if ((item.username == $scope.user.username) && (item.password == $scope.user.password)) {
                    }
                    stat = "true";
                });
                $scope.user.username = "";
                $scope.user.password = "";
                if (stat == "true" && item.userid == 22) {
                    //debugger;
                    $sessionStorage.SessionMessage = response.data;
                    window.location.href = 'http://stagingserver:85/EBSAjs/Views/Warehouse/receipt.html';
                }
                else {                    
                    alert("Access denied!");
                    $sessionStorage.reset();                   
                }
            })
        });
    }; 
    $scope.user = {
        "username": "",
        "password": ""
    };
});

receipt.js :

var app = angular.module('AngulardateApp', ['ngStorage', 'angucomplete-alt']);
app.controller('datectrl', function ($scope, $sessionStorage, $http) {
    //to display date and time
    $scope.currentdate = new Date();

    //to get username from the login page and display it in this page
    debugger;
    var user = JSON.parse($sessionStorage.SessionMessage.replace('[', '').replace(']', ''));
    user.username = user.username.substring(0, 1).toUpperCase() + user.username.substring(1, user.username.length);
    $scope.username = user.username;
    //alert($scope.username);