Program To Validate the USN of the Student and Print them using JavaScript

 Code:

<!DOCTYPE html>

<html>

<head>

<meta charset="utf-8">

<meta name="viewport" content="width=device-width, initial-scale=1">

<title>Demo USN Validator</title>

<script>

function formValidator()

{

var usn=document.getElementById('usnFrm');

usnExp=/\d{9}$/

if(usn.value.length==0)

{

alert("USN is Empty");

usn.focus();

return false;

}

else if (!usn.value.match(usnExp))

{

alert("USN Should be in Srinivas University USN Format eg.,102272693");

usn.focus();

return false;

}

alert("USN: "+usn.value+" is in Correct Format");

return true;

}

</script>

</head>

<body>

<form onSubmit="formValidator()">

Enter Your SU USN: <input type="text" id="usnFrm"/>

<br>

<input type="submit" value="SUBMIT"/ >

</form>

</body>

</html>

Output: