//form-xhf--2009-05-27
var speed = 20;
var offset = 1;
var delay = 3000;
var cur = 0;
var roll_interval;
var pasue_timeout;
var now_pos;
var now_scrolltop;
var big_news = document.getElementsByName("big_news");
var varnum;
function roll() {
    varnum = document.getElementById("roll_layer").scrollTop;
    document.getElementById("roll_layer").scrollTop += offset;
        if (varnum == document.getElementById("roll_layer").scrollTop) {
            stop_roll();
            text_switch();
            document.getElementById("roll_layer").scrollTop = 0;
            pasue_timeout = window.setTimeout("start_roll();", delay);
        }
}
function stop_roll() {
    window.clearInterval(roll_interval);
}
function start_roll() {
    window.clearTimeout(pasue_timeout);
    roll_interval = window.setInterval('roll()', speed);
}
function text_switch() {
    document.getElementById("roll_layer").innerHTML = big_news[cur].innerHTML;
    if (++cur == big_news.length) {
        cur = 0;
    }
    document.getElementById("roll_layer").innerHTML += big_news[cur].innerHTML;
    now_scrolltop = document.getElementById("roll_layer").scrollTop;
    now_pos = document.getElementById("roll_layer").offsetHeight
}
function stop_timeout() {
    if (document.getElementById("roll_layer").scrollTop != 0)
    { stop_roll(); }
    
}
function star_timeout() {
    if (document.getElementById("roll_layer").scrollTop != 0)
    { start_roll(); } 
}
function start() {
    text_switch();
    window.setTimeout("start_roll();", 3000);
}