function pageLeft(elem){
       return elem.offsetParent ? elem.offsetLeft + pageLeft( elem.offsetParent ) : elem.offsetLeft;
}
function pageTop(elem){
       return elem.offsetParent ? elem.offsetTop + pageTop( elem.offsetParent ) : elem.offsetTop;
}
function getEventObject(W3CEvent) {                     //???????
       return W3CEvent || window.event;
}
function getPointerPosition(e) {                     //????????x,y????
       e = e || getEventObject(e);
       var x = e.pageX || (e.clientX + (document.documentElement.scrollLeft || document.body.scrollLeft));
       var y = e.pageY || (e.clientY + (document.documentElement.scrollTop || document.body.scrollTop));
       
       return { 'x':x,'y':y };
}
function setOpacity(elem,level) {                     //??????????
       if(elem.filters) {
              elem.style.filter = 'alpha(opacity=' + level * 100 + ')';
       } else {
              elem.style.opacity = level;
       }
}
function css(elem,prop) {                            //css????,??????css?,?????????
       for(var i in prop) {
              if(i == 'opacity') {
                     setOpacity(elem,prop[i]);
              } else {
                     elem.style[i] = prop[i];
              }
       }
       return elem;
}
var magnifier = {
       m : null,
       
       init:function(magni){
              var m = this.m = magni || {
                     cont : null,              //???????div
                     img : null,                     //?????
                     mag : null,                     //???
                     scale : 1                     //???,??????????,??????????????????,?????????,?????????
              }
              
              css(m.img,{       
                     'position' : 'absolute',
                     'width' : (m.cont.clientWidth * m.scale) + 'px',                            //??????*???       
                     'height' : (m.cont.clientHeight * m.scale) + 'px'                            //??????*???
                     })
              
              css(m.mag,{
                     'display' : 'none',
                     'width' : m.cont.clientWidth *1.2 + 'px',                     //m.cont?????,???????
                     'height' : m.cont.clientHeight *1.2 + 'px',
                     'position' : 'absolute',
                     'left' : m.cont.offsetLeft + m.cont.offsetWidth + 10 + 'px',              //???????????????10px
                     'top' : m.cont.offsetTop + 'px'
                     })
              
              var borderWid = m.cont.getElementsByTagName('div')[0].offsetWidth - m.cont.getElementsByTagName('div')[0].clientWidth;              //??border??
              
              css(m.cont.getElementsByTagName('div')[0],{                     //m.cont.getElementsByTagName('div')[0]????
                     'display' : 'none',                                                        //????????
                     'width' : m.cont.clientWidth *1.2 / m.scale - borderWid + 'px',                     //??????/??? - border???
                     'height' : m.cont.clientHeight *1.2 / m.scale - borderWid + 'px',              //??????/??? - border???
                     'opacity' : 0.5                                   //?????
                     })
              
              m.img.src = m.cont.getElementsByTagName('img')[0].src;                     //??????src???????
              m.cont.style.cursor = 'crosshair';
              
              m.cont.onmouseover = magnifier.start;
              
       },
       
       start:function(e){
              
              if(document.all){                            //??IE???,????IE6?select????
                     magnifier.createIframe(magnifier.m.img);
              }
              
              this.onmousemove = magnifier.move;              //this??m.cont
              this.onmouseout = magnifier.end;
       },
       
       move:function(e){
              var pos = getPointerPosition(e);              //?????
              
              this.getElementsByTagName('div')[0].style.display = '';
              
              css(this.getElementsByTagName('div')[0],{
                     'top' : Math.min(Math.max(pos.y - pageTop(this) - parseInt(this.getElementsByTagName('div')[0].style.height) / 2,0),this.clientHeight - this.getElementsByTagName('div')[0].offsetHeight) + 'px',
                     'left' : Math.min(Math.max(pos.x - pageLeft(this) - parseInt(this.getElementsByTagName('div')[0].style.width) / 2,0),this.clientWidth - this.getElementsByTagName('div')[0].offsetWidth) + 'px'                     //left=??x - this.offsetLeft - ????/2,Math.max?Math.min??????????
                     })
              
              magnifier.m.mag.style.display = '';
              
              css(magnifier.m.img,{
                     'top' : - (parseInt(this.getElementsByTagName('div')[0].style.top) * magnifier.m.scale) + 'px',
                     'left' : - (parseInt(this.getElementsByTagName('div')[0].style.left) * magnifier.m.scale) + 'px'
                     })
              
       },
       
       end:function(e){
              this.getElementsByTagName('div')[0].style.display = 'none';
              magnifier.removeIframe(magnifier.m.img);              //??iframe
              
              magnifier.m.mag.style.display = 'none';
       },
       
       createIframe:function(elem){
              var layer = document.createElement('iframe');
              layer.tabIndex = '-1';
              layer.src = 'javascript:false;';
              elem.parentNode.appendChild(layer);
              
              layer.style.width = elem.offsetWidth + 'px';
              layer.style.height = elem.offsetHeight + 'px';
       },
       
       removeIframe:function(elem){
              var layers = elem.parentNode.getElementsByTagName('iframe');
              while(layers.length >0){
                     layers[0].parentNode.removeChild(layers[0]);
              }
       }
}
window.onload = function(){
       magnifier.init({
                               cont : document.getElementById('magnifier'),
                               img : document.getElementById('magnifierImg'),
                               mag : document.getElementById('mag'),
                               scale : document.getElementById('Scale').value
                               });
}