function scoreGrade(){ var score = prompt('점수를 입력하세요!',''); var grade; if(score<60){ grade='F'; }else if(score>=60 && score<70){ grade='D'; }else if(score>=70 && score<80){ grade='C'; }else if(score>=80 && score<90){ grade='B'; }else { grade='A'; } document.getElementById('score').innerHTML = '점수: ' + score + '<br>'; document.getElementById('grade').innerHTML = '등급: ' + grade + '<br>'; }