function getPositionByEvent(evt) {
    evt = (evt) ? evt : ((window.event) ? event : null); 
    if(evt) {
        var who = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);
        var offsetTrail = who;
        var offsetLeft = 0;
        var offsetTop = 0;
        while(offsetTrail){
            offsetLeft += offsetTrail.offsetLeft;
            offsetTop += offsetTrail.offsetTop;
            offsetTrail = offsetTrail.offsetParent;
        }
        return{left:offsetLeft, top:offsetTop};
    }
}
function showEvent(evt, msg) {
    var elemId = document.getElementById('eventBody');
    var xc = getPositionByEvent(evt).left;
    var yc = getPositionByEvent(evt).top;
    elemId.style.top = yc+'px';
    elemId.style.left = xc+1+'px';
    elemId.style.display = 'block';
    elemId.innerHTML = msg;
}
function hideEvent(evt) {
    evt = (evt) ? evt : ((window.event) ? event : null); 
    if(evt) {
        var who = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);
        who.style.display = 'none';
    }
}
function hideEventDirect(elemId) {
    var who = document.getElementById(elemId);
    who.style.display = 'none';
}