function toggleExpander(){
    var manager = document.getElementById('citationManagerList');
    //update image
    if(document.manager_expander.src == 'http://citastic.com/images/manager_expander.gif'){
        document.manager_expander.src = 'images/manager_contractor.gif';
    }
    else{
        document.manager_expander.src = 'images/manager_expander.gif';
    }
    //update height/maxHeight combination
    if(manager.style.height == ''){
        manager.style.height='75px';
        manager.style.maxHeight='75px';
    }
    else{
        manager.style.height='';
        manager.style.maxHeight='';
    }
}