function startClock () {
    var startClock = setInterval(function(){
        if (countdown > 0 ) {
        timer.textContent = countdown; 
        countdown--;
        }
        else if (countdown === 0) {
            clearInterval(startClock);
            endQuiz();
        }
        else if (countdown === "clear") {
            clearInterval(startClock);
        }
    }, 1000);       
}
// timer function to start countdown after start quiz button pushed
timer function to start countdown after start quiz button pushed
timer function to start countdown after start quiz button pushed
function startClock () {
    var startClock = setInterval(function(){
        if (countdown > 0 ) {
        timer.textContent = countdown; 
        countdown--;
        }
        else if (countdown === 0) {
            clearInterval(startClock);
            endQuiz();
        }
        else if (countdown === "clear") {
            clearInterval(startClock);
        }
    }, 1000);       
}
function startClock ( ) { var startClock = setInterval ( function ( ) { if ( countdown > 0 ) { timer . textContent = countdown ; countdown -- ; } else if ( countdown === 0 ) { clearInterval ( startClock ) ; endQuiz ( ) ; } else if ( countdown === "clear" ) { clearInterval ( startClock ) ; } } , 1000 ) ; }
timer function to start countdown after start quiz button pushed
timer function to start countdown after start quiz button pushed