function changeopacity( imageobject, opacity ) {
    var object = document.getElementById(imageobject).style;
    try { object.opacity = ( opacity / 100 ) } catch (err) {};
    try { object.MozOpacity = ( opacity / 100 ) } catch (err) {};
    try { object.KhtmlOpacity = ( opacity / 100 ) } catch (err) {};
    try { object.filter = "alpha(opacity=" + opacity + ")" } catch (err) {};
}