/**
 "a" defines the action you want the function to perform.
 Possible actions are:
 swap:	replaces class c1 with class c2 in object o.
 add:    adds class c1 to the object o.
 remove:	removes class c1 from the object o.
 check:	test if class c1 is already applied to object o and returns true or false.
 */
function jscss(a, o, c1, c2){
    switch (a) {
        case 'swap':
            o.className = !jscss('check', o, c1) ? o.className.replace(c2, c1) : o.className.replace(c1, c2);
            break;
        case 'add':
            if (!jscss('check', o, c1)) {
                o.className += o.className ? ' ' + c1 : c1;
            }
            break;
        case 'remove':
            var rep = o.className.match(' ' + c1) ? ' ' + c1 : c1;
            o.className = o.className.replace(rep, '');
            break;
        case 'check':
            return new RegExp('\\b' + c1 + '\\b').test(o.className)
            break;
    }
}