// General purpose functions. 

function hide_element(elementId) {
    element = document.getElementById(elementId);
    if(element != null) {
        currentClass = element.className;
        if(currentClass =='visible_tooltip') {
            element.className = 'hidden_tooltip';
        }
    }
}

function show_element(elementId) {
    element = document.getElementById(elementId);
    if(element != null) {
        currentClass = element.className;
        if(currentClass == 'hidden_tooltip') {
            element.className = 'visible_tooltip';
        }
    }
}