function returnToMenu() {
    indexMenu.style.display = 'grid';
    startModule.style.display = 'none';
    document.getElementById('case-doctor').style.visibility = "visible";
}
//if the user wants to return to menu
if the user wants to return to menu
if the user wants to return to menu
function returnToMenu() {
    indexMenu.style.display = 'grid';
    startModule.style.display = 'none';
    document.getElementById('case-doctor').style.visibility = "visible";
}
function returnToMenu ( ) { indexMenu . style . display = 'grid' ; startModule . style . display = 'none' ; document . getElementById ( 'case-doctor' ) . style . visibility = "visible" ; }
if the user wants to return to menu
if the user wants to return to menu