Quick explanation: my logic is failing me

programming web dev
1

This code keeps returning multiple values according to where the value is on the list. IE: The 5th checkbox returns one value, the 4th returns the same one twice. Can anyone explain to me why this is happening?


function filterCal() {
        var filterValues = "";
        for (var i=0; i < document.categories.music.length; i++) {
            if (document.categories.music*.checked) {
                filterValues = filterValues + document.categories.music*.value + "
";
            }
            document.write(filterValues);
        }
    }