function changeState(oldState, newState) {
     element.classList.remove(getCSSClassName(oldState));
     element.classList.add(getCSSClassName(newState));
}

function changeState(oldState, newState) {
     var str = element.className;
     str = str.replace(getCSSClassName(oldState),"");
     str = str + getCSSClassName(newState);
     element.className = str;
}