// simple scroller (c) 2009 chime interactive www.chime.com
var _scrollId;
var _scrollAmt;
var _SLOW_SCROLL = 5;
var _FAST_SCROLL = 50;
var _SCROLL_INTERVAL = 50; // ms

function start_scroll (contentID, amt) {   
    var cobj = document.getElementById(contentID);
    stop_scroll();

    if ( ! cobj || cobj.style.display == "none" )
        return;

    _scrollAmt = amt;
    _scrollId = setInterval ("scroll('" + contentID + "')", _SCROLL_INTERVAL);
}

function stop_scroll () {   
    if ( _scrollId )
    {   
        clearInterval (_scrollId);
        _scrollId = undefined;
    }
}

function scroll_amt (amt) {   
    _scrollAmt = amt;
}

function scroll (contentID) {   
    var cobj = document.getElementById(contentID);

    cobj.scrollLeft += _scrollAmt;

    if ( _scrollAmt < 0 )
    {   
        if ( cobj.scrollLeft == 0 )
            stop_scroll();
    }
    else
    {   
        if ( cobj.scrollLeft == cobj.scrollWidth )
            stop_scroll();
    }
}