CIS 119 Receive and unescape a get request

Received data

The JavaScript code

function $(id) {
    return document.getElementById(id);
}

window.onload = function() {
    var out = "";
    var queryString = window.location.search.substring(1);
    if (queryString.length == 0) {
        out += "Error: no fields found";
    } else {
        var fields = queryString.split('&');
        for (var i=0; i<fields.length; i++) {
            var key = fields[i].split('=')[0];
            var value = unescape(fields[i].split('=')[1]);
            out += '<p>Key: ' + key + ', Value: ' + value + '</p>';
        }
        $('result').innerHTML = out;
    }
};