var maxW,maxH,fromX,fromY,toX,toY,adjX,adjY,zBox,zStep=0,zLink,zNew;

function zoomBox(evt,zlink,maxw,maxh,tox,toy) {
    if (arguments.length > 2) zNew=1;
    scrollH=(window.pageYOffset!=null)?window.pageYOffset:document.body.scrollTop;
    maxW=maxw?maxw:window.innerWidth?innerWidth:document.body.clientWidth;
    maxH=maxh?maxh:window.innerHeight?innerHeight:document.body.clientHeight;
    toX=tox?tox:0;
    toY=(toy?toy:0)+scrollH;
    fromX=evt.pageX?evt.pageX:evt.clientX;
    fromY=(evt.pageY?evt.pageY:evt.clientY)+(document.all?scrollH:0);
    adjX=toX+evt.screenX-fromX;
    adjY=toY+evt.screenY-fromY;

    if (document.createElement && document.body.appendChild && !zBox) {
        zBox=document.createElement("div");
        zBox.style.position="absolute";
        document.body.appendChild(zBox);
    } else if (document.all && !zBox) {
        document.all[document.all.length-1].outerHTML+='<div id="zBoxDiv" style="position:absolute"></div>';
        zBox=document.all.zBoxDiv;
    } else if (document.layers && !zBox) {
        zBox=new Layer(maxW);
        zBox.style=zBox;
    }
    zLink=zlink;
    doZoom();
}

function doZoom() {
    zStep+=1;
    zPct=(10-zStep)/10
    var toX = (screen.width - maxW) / 2;
    var toY = (screen.height - maxH) / 2;
    if (document.layers) {
        zBox.moveTo(toX+zPct*(fromX-toX),toY+zPct*(fromY-toY));
        zBox.document.open();
        zBox.document.write("<table width='"+maxW*(1-zPct)+"' height="+maxH*(1-zPct)+" border=2 cellspacing=0><tr><td></td></tr></table>");
        zBox.document.close();
    } else {
        zBox.style.border="2px solid #999999";
        zBox.style.left=toX+zPct*(fromX-toX);
        zBox.style.top=toY+zPct*(fromY-toY);
        zBox.style.width=maxW*(1-zPct);
        zBox.style.height=maxH*(1-zPct);
    }
    zBox.style.visibility="visible";
    if (zStep < 10) setTimeout("doZoom("+fromX+","+fromY+","+toX+","+toY+")",30);
    else {
        zBox.style.visibility='hidden';
        zStep=0;

        if (zLink && !zNew) location.href=zLink.href;
        else if (zLink && zNew) {
            var winLeft = (screen.width - maxW) / 2;
            var winTop = (screen.height - maxH) / 2;
            winData = 'width='+maxW+',height='+maxH+',left='+winLeft+',top='+winTop+' ';
            var w = window.open(zLink.href, '', winData);
            zNew=null;
        }
    }
}