formvalidation.html

<!DOCTYPE html>
<html>
    <head>
    <title>Contact Details</title>
    <script type="application/javascript">
        function checkdata(){
            //Create references to the input elements we wish to validate
            var username = document.getElementById("name");
            var email_address = document.getElementById("email");

            //Check if username field is empty
            if(username.value == ""){
                    alert("Please enter the name");
                    username.focus();
                    return false;
            }
            //Check if email field is empty
            if(email_address.value == ""){
                    alert("Please enter the email");
                    email_address.focus();
                    return false;
            }
            //If all is well return true.
            return true;
        }
    </script>
    </head>
    <body>
        <h2>Enter your contact details:</h2> <br>
        <form id="form1" onsubmit="return checkdata()">
            <label for="name">Name:</label>
            <input type="text" id="name" name="name">
            <br><br>
            <label for="email">Email Address:</label>
            <input type="text" id="email" name="email">
            <br><br>
            <input type="submit" value="Submit">
            <input type="reset" value="Reset">
        </form>
    </body>
</html>