/*
* 
* ImageScroller - a Image Horizental Scroll Viewer 
* Version 0.1
* @requires jQuery v1.2.1
* 
* Copyright (c) 2007 Luan
* Email verycss-ok@yahoo.com.cn 
* 
* Dual licensed under the MIT and GPL licenses:
* http://www.opensource.org/licenses/mit-license.php
* http://www.gnu.org/licenses/gpl.html
* 
* Example:
*   #viewer {height:100px; width:300px; clear:both; overflow:hidden; border:3px solid #e5e5e5;}
*   #viewerFrame {width:505px; clear:both; padding:0;}
*   #viewer img {width:90px; height:90px; margin:5px; display:inline; border:0;}
*   #viewer a {display:block; float:left; width:100px; height:100px;}
*   <script type="text/javascript">
*   $(function(){
*   	$("#viewer").imageScroller({
*   	next:"btn1",
*   	prev:"btn2",
*   	frame:"viewerFrame",
*   	child:"a",
*   	auto:true
*   	});	 
*   });
*   </script>
*   <div id="viewer"><div id="viewerFrame">
*   <a href=""><img src="pre1.jpg"></a>
*   <a href=""><img src="pre2.jpg"></a>
*   <a href=""><img src="pre3.jpg"></a>
*   <a href=""><img src="pre4.jpg"></a>
*   <a href=""><img src="pre5.jpg"></a>
*   </div></div>
*   <span id="btn1">prev</span><br/><span id="btn2">next</span>   
*/

jQuery.fn.imageScroller = function(params) {
    var p = params || {
        next: "buttonNext",
        prev: "buttonPrev",
        frame: "viewerFrame",
        child: "a",
        auto: true
    };
    var _btnNext = $("#" + p.next);
    var _btnPrev = $("#" + p.prev);
    var _imgFrame = $("#" + p.frame);
    var _child = p.child;
    var _auto = p.auto;
    var _itv;

    var turnLeft = function() {
        _btnPrev.unbind("click", turnLeft);
        if (_auto) autoStop();
        _imgFrame.animate({ marginLeft: -95 }, 'fast', '', function() {
            _imgFrame.find(_child + ":first").appendTo(_imgFrame);
            _imgFrame.css("marginLeft", 0);
            _btnPrev.bind("click", turnLeft);
            if (_auto) autoPlay();
        });
    };

    var turnRight = function() {
        _btnNext.unbind("click", turnRight);
        if (_auto) autoStop();
        _imgFrame.find(_child + ":last").clone().show().prependTo(_imgFrame);
        _imgFrame.css("marginLeft", -95);
        _imgFrame.animate({ marginLeft: 0 }, 'fast', '', function() {
            _imgFrame.find(_child + ":last").remove();
            _btnNext.bind("click", turnRight);
            if (_auto) autoPlay();
        });
    };

    _btnNext.css("cursor", "hand").click(turnRight);
    _btnPrev.css("cursor", "hand").click(turnLeft);

    var autoPlay = function() {
        _itv = window.setInterval(turnLeft, 3000);
    };
    var autoStop = function() {
        window.clearInterval(_itv);
    };
    if (_auto) autoPlay();
};