function calculatePopupOffset(zoom, height) {
    //function to calculate popup window offset based on zoom level - just a best guess effort
    var offSetArray = new Array();
    var index = 1;
    
    //position based on height of popup
    if (height > 200) {
        var lat = 90;
    }
    else {
        var lat = 50;
    }
    
    var lon = 76.8;
    
    for (var i = index; i < zoom; i++) {
        lat = lat/2;
        lon = lon/2;
    }
    offSetArray[0] = lat;
    offSetArray[1] = lon;
    
    return offSetArray;
}