Question

I have a login box using a simple javascript login comparing usernames and passwords, before you all start I know about the security issues in using javascript for authentication. Here is the code

function validate() {
    var un = document.getElementById("usern").value;
    var pw = document.getElementById("pword").value;
    var valid = false;

    var unArray = ["markwalt", "jongossy", "lisacain", "jenndemp"];
    var pwArray = ["mark1234", "flomaygo", "lisa1234", "jenny1234"];
    var fnArray = ["Mark Walters", "Jonathan Goss", "Lisa Cain", "Jenny Dempsey"];

    for (var i=0; i <unArray.length; i++) {
        if ((un == unArray[i]) && (pw == pwArray[i])) {
            valid = true;
            break;
        }
    }

    if (valid) {
        alert ("Login was successful");
        document.getElementById("mandatory1").value = un;
    }
    else {
        alert("Invalid Username and/or Password! Please try again. You will not be able to submit this form without a successful login")
        document.getElementById("pword").value = "";
        document.getElementById("usern").value = "";
        document.getElementById("usern").focus();
    }
}

At the moment if the login is successful I’m posting the username to a hidden field which is then being used by a piece of a software. How do I associate the names in fnArray with the other correct username & password so that I can then grab associated full name and post that to the hidden field “mandator1” instead?

Answer 1

Define a variable for full name, and set it if you have the valid user:

var fn = "";

/* ... */

valid = true;
fn = fnArray[i];

/* ... */

document.getElementById("mandatory1").value = fn;

Note: Actually you can check validity later on using fn. If it is empty string, then no user was logged in. This makes it have same purpose as valid, and more.