function setTheme(theme)
{
    if ( !window.name )
        window.name='t01';
    document.getElementById(window.name).disabled=true;
    document.getElementById(theme).disabled=false;
    window.name=theme;
    return false;
}

function setDefaultTheme()
{
    var current;

    document.getElementById('t01').disabled=true;
    document.getElementById('t02').disabled=true;
    if ( window.name )
    {
        current=window.name;
        window.name='t01';
        setTheme(current);
    }
}

setDefaultTheme();