<script>

    window.onload = function() {

        var welcome = document.getElementById('welcome');
        var requirement = document.getElementById('requirement');
        var permission = document.getElementById('permission');
        var environment = document.getElementById('environment');
        var migration = document.getElementById('migration');
        var admin =  document.getElementById('admin');

        var welcomeCheck = document.getElementById('welcome-check');
        var requirementCheck = document.getElementById('requirement-check');
        var permisssionCheck = document.getElementById('permission-check');
        var environmentCheck = document.getElementById('environment-check');
        var continue_to_admin =  document.getElementById('continue');

        var permissionBack = document.getElementById('permission-back');
        var requirementBack = document.getElementById('requirement-back');
        var envBack = document.getElementById('envronment-back');
        var migrationBack = document.getElementById('migration-back');

        if (requirementCheck) {
            requirementCheck.addEventListener('click', myFunction);
        }

        if (welcomeCheck) {
            welcomeCheck.addEventListener('click', myFunction);
        }

        if (permisssionCheck) {
            permisssionCheck.addEventListener('click', myFunction);
        }

        if (environmentCheck) {
            environmentCheck.addEventListener('click', myFunction);
        }

        if (continue_to_admin) {
            continue_to_admin.addEventListener('click', myFunction);
        }

        if (envBack) {
            envBack.addEventListener('click', myFunction);
        }

        if (requirementBack) {
            requirementBack.addEventListener('click', myFunction);
        }

        if (permissionBack) {
            permissionBack.addEventListener('click', myFunction);
        }

        if (migrationBack) {
            migrationBack.addEventListener('click', myFunction);
        }


        function myFunction() {
            if(this.id == 'welcome-check') {
                requirement.style.display = "block";
                welcome.style.display = "none";
            } else if (this.id == 'requirement-check') {
                environment.style.display = "block";
                requirement.style.display = "none";
            } else if (this.id == 'continue') {
                migration.style.display = "none";
                admin.style.display ="block";
            } else if (this.id == 'requirement-back') {
                welcome.style.display = "block";
                requirement.style.display = "none";
            } else if (this.id == 'envronment-back') {
                environment.style.display ="none";
                requirement.style.display = "block";
            } else if (this.id == 'migration-back') {
                migration.style.display = "none";
                environment.style.display ="block";
            }
        }
    };

</script>