Untitled-4.html

<html>
<body>
    <h2>Student Grade Calculator</h2>
    <p>Enter the student's mark:</p>
    <input type="number" id="mark" min="0" max="100">
    <button onclick="calculateGrade()">Calculate Grade</button>
    <p id="result"></p>

    <script>
        function calculateGrade() {
            var mark = document.getElementById("mark").value;
            var grade = "";

            if (mark > 100 || mark < 0) {
                grade = "Invalid mark. Please enter a mark between 0 and 100.";
            } else if (mark > 70) {
                grade = "A";
            } else if (mark >= 60) {
                grade = "B";
            } else if (mark >= 50) {
                grade = "C";
            } else if (mark >= 40) {
                grade = "D";
            } else {
                grade = "E";
            }

            document.getElementById("result").innerHTML = "Grade: " + grade;
        }
    </script>
</body>
</html>