function doOverEffect(oEvent)
{
    var obj = getObjectFromEvent(oEvent);
    obj.src = obj.src.replace(".gif","_over.gif")
     obj.src = obj.src.replace("_down.gif","_over.gif")
}
function getObjectFromEvent(oEvent)
{
    return (oEvent.target || oEvent.srcElement);
}
    
function doOutEffect(oEvent)
{
    var obj = getObjectFromEvent(oEvent);
    obj.src = obj.src.replace("_over.gif",".gif");
    obj.src = obj.src.replace("_down.gif",".gif")
}


function openPresentation()
{
    location.href = "presentation.aspx";
}