function updateUser() {
            // Create a new object to contain the data in the loginForm.
            // We assign the new object to a variable called "credentials".
            var updateUser = new Object();

            updateUser.username = getCookie("username");
            updateUser.first_name = document.getElementById("firstname").value;
            updateUser.last_name = document.getElementById("lastname").value;
            updateUser.email = document.getElementById("email").value;
            updateUser.phone_number = document.getElementById("phonenumber").value;
            updateUser.password = document.getElementById("password").value;

            var repeatpassword = document.getElementById("repeatpassword").value;

            if (updateUser.password != repeatpassword) {
                alert("Password do not match!");
                return;
            }

            //if given first name input is empty.
            if (isEmptyOrSpaces(updateUser.first_name)) {
                updateUser.first_name = gb_First_Name;
            }

            //if give last name input is empty
            if (isEmptyOrSpaces(updateUser.last_name)) {
                updateUser.last_name = gb_Last_Name;
            }

            //if email input is empty
            if (isEmptyOrSpaces(updateUser.email)) {
                updateUser.email = gb_Email;
            }

            //if phone number input is empty
            if (isEmptyOrSpaces(updateUser.phone_number)) {
                updateUser.phone_number = gb_PhoneNumber;
            }

            //if password input is empty
            if (isEmptyOrSpaces(updateUser.password)) {
                updateUser.password = gb_Password;
            }


            var putUser = new XMLHttpRequest();

            putUser.open("PUT", "/updateUser", true);

            putUser.setRequestHeader("Content-Type", "application/json");
            putUser.onload = function () {
                var response = JSON.parse(request.responseText);

                //if update is successful
                if (response.message == "PASS") {
                    alert("Update successful!");
                } else {
                    alert("Update failed")
                }

            };

            putUser.send(JSON.stringify(updateUser));
        }