function getObjectRefByID(objectId) {
    // cross-browser function to get an object given its id
    if(this.document.getElementById && this.document.getElementById(objectId)) {
        // W3C DOM
        return this.document.getElementById(objectId);
    } 
    else if (this.document.all && this.document.all(objectId)) {
        // MSIE 4 DOM
        return this.document.all(objectId);
    } 
    else if (this.document.layers && this.document.layers[objectId]) {
        // NN 4 DOM.. note: this won't find nested layers
        return this.document.layers[objectId];
    } 
    else {
        return false;
    }
} 

function toggleObjectVisiblity(objID,link) {
    var obj = getObjectRefByID(objID);
    if(obj.className == 'hidden'){
        obj.className = 'visible';
    } else {
        obj.className = 'hidden';
    }
    if(link){
        if(link.innerHTML == '-'){
            link.innerHTML = '+';
        } else if (link.innerHTML == '+'){
            link.innerHTML = '-';
        }
    }

    return false;
}