function avgScore(n,m,f)
{
    var a = n * 0.3 + m * 0.3 + f * 0.4;
    return a;
}
function ScoreLevel(avg)
{
    if (90 <= avg) {
        level = 'A';
    }
    else if (80 <= avg && avg <= 89) {
        level = 'B';
    }
    else if (70 <= avg && avg<= 79) {
        level = 'C';
    }
    else if (60 <= avg && avg<= 69) {
        level = 'D';
    }
    else if (avg < 60) {
        level = 'F';
    }
    return level;
}
do
{
    var name = prompt("請輸入你的姓名", "")
    var nScore = prompt("請輸入你的平時分數", "")
    var mScore = prompt("請輸入你的期中分數", "")
    var fScore = prompt("請輸入你的期末分數", "")
    var avg = avgScore(nScore, mScore, fScore);
    var level = ScoreLevel(avg)
    var YorN = prompt("是否繼續(Y/N)?", "")
    var Students = new Array(1);
        for (var i = 0; i < Students.length; i++)
            Students[i] = new Array(6);
        Students[0][0] = "  " + name;
        Students[0][1] = "  " + nScore;
        Students[0][2] = "  " + mScore;
        Students[0][3] = "  " + fScore;
        Students[0][4] = "  " + avg;
        Students[0][5] = "  " + level;
        for (var i = 0; i < Students.length; i++)
        {
            document.write("<tr>");
            for (var j = 0; j < Students[i].length; j++)
                document.write("<td>" + Students[i][j] + "</td>");
            document.write("</tr>");
        }
}while ( YorN == 'Y')