2.2.html

<!DOCTYPE html>
<html lang="en">

<head>
   <meta charset="UTF-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>Assignment 2 Qn 2</title>
   <script>
      function validate() {
         let x = document.getElementById("roll").value;
         var num = /^[0-9]+$/;
         if (!x.match(num))
            alert("The roll number must be of numeric value!");
         else if (x.toString().length != 7)
            alert("The length of roll no. must be greater than 7!!!");
         else
            alert("Valid!");
      }
   </script>
</head>

<body style="text-align: center;">
   <h2>Student Registration form</h2>
   <form action="">
      <label for="name">Enter your name:</label>
      <input type="text" name="name" id="name" placeholder="Your name..."><br><br>
      <label for="roll">Enter your Roll Number:</label>
      <input type="text" name="roll" id="roll" placeholder="Your roll number..."><br><br>
      <label for="course">Enter the courses you attend:</label>
      <input type="text" name="course" id="course" placeholder="Your courses..."
         style="width: 50ch; height: 10ch;"><br><br>
      <input type="submit" onclick="validate()" placeholder="Submit">
   </form>
</body>

</html>