// JavaScript Document

var divObj = null;
var imgObj = null;
var imgWidth = 172;
var timeID = null;
var n = null;
var l = null;
var arrow = 1;

function picScrolls_init(){
    divObj = document.getElementById("picScroll");
    imgObj = divObj.getElementsByTagName("li");
    n = imgObj.length - 1;
    l = 0;
    for(i=0; i<imgObj.length; i++){
        imgObj[i].style.position = "absolute";
        imgObj[i].style.left = (i * imgWidth) + "px";
    }
    picScrolls_move();
}

function picScrolls_move(){
    picScroll_move_stop();
    for(i=0; i<imgObj.length; i++){
        imgObj[i].style.left = (parseInt(imgObj[i].style.left.replace("px", "")) - arrow) + "px";
    }

    if(arrow > 0){
        nowRight = parseInt(imgObj[n].style.left.replace("px", "")) + imgWidth;
        if(divObj.offsetWidth >= nowRight){
            picScrolls_set_basic();
            imgObj[n].style.left = nowRight + "px";
        }
    }else{
        nowLeft = parseInt(imgObj[l].style.left.replace("px", ""));
        if(0 <= nowLeft){
            picScrolls_set_basic();
            imgObj[l].style.left = (nowLeft - imgWidth)  + "px";
        }
    }
    picScroll_move_start();
}

function picScrolls_set_basic(){
    if(arrow > 0){
        n++;
        if(n >= imgObj.length){
            n = 0;
        }
        l++;
        if(l >= imgObj.length){
            l = 0;
        }
    }else{
        l--;
        if(l < 0){
            l = imgObj.length - 1;
        }
        n--;
        if(n < 0){
            n = imgObj.length - 1;
        }
    }
}

function picScroll_move_start(){
    timeID = setTimeout(picScrolls_move, 15);
}

function picScroll_move_stop(){
    clearTimeout(timeID);
}

function  picScroll_move_left(){
    picScroll_move_stop();
    arrow = 1;
    picScroll_move_start();
}

function  picScroll_move_right(){
    picScroll_move_stop();
    arrow = -1;
    picScroll_move_start();
}

window.onload = function(){
    picScrolls_init();
}