JavaScript If...else if statement

It evaluates the content only if expression is true from several expressions. The signature of JavaScript if else if statement is given below.

if(expression1){  
     //content to be evaluated if expression1 is true  
}  
else if(expression2){  
    //content to be evaluated if expression2 is true  
}  
else if(expression3){  
    //content to be evaluated if expression3 is true  
}  
else{  
    //content to be evaluated if no expression is true  
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>JavaScript</title>
    <script>
        /* If Else IF Condition */
        var per = prompt("Enter your Percentage : ");

        if (per >= 80 && per <= 100) {
            document.write("You are in Merit.");
        }else  if (per >= 60 && per < 80) {
            document.write("You are in Ist Division.");
        }else if (per >= 45 && per < 60) {
            document.write("You are in IIst Division.");
        }else if (per >= 33 && per < 45) {
            document.write("You are in IIIst Division.");
        }else if (per < 33) {
            document.write("You are Fail.");
        }else {
            document.write("Please Enter Valid Percentage.");  
        }
    </script>
</head>
<body>
</body>
</html>