var IE = document.all?true:false;
if (!IE) document.captureEvents(Event.MOUSEMOVE)

var tempX   = 0;
var tempY   = 0;
var idImg   = "img-pequena-2"; // id da imagem a ampliar
var moveDiv = "img-popup-2";
var idImgG  = "img-grande-2";
var onDrag  = false;

function mudaId(id){
    idImg = "img-pequena-" + id;
    moveDiv = "img-popup-" + id;
    idImgG  = "img-grande-" + id;
}

function getMouseXY(e) {

    if (IE) { // grab the x-y pos.s if browser is IE
        tempX = event.clientX + document.body.scrollLeft;
        tempY = event.clientY + document.body.scrollTop;
    } else {  // grab the x-y pos.s if browser is NS
        tempX = e.pageX;
        tempY = e.pageY;
    }
    if (tempX < 0){tempX = 0;}
    if (tempY < 0){tempY = 0;}

    dragExec(e);

    return true;
}

function dragExec(e) {
    var el = IE ? event.srcElement : e.target;
    var top, left;

    if( el.id == idImg ) { // se o id corresponder a ao da imagem a ampliar entao mostra popup
        startDrag(e, moveDiv);
        dMove = document.getElementById(moveDiv);
        dImgG = document.getElementById(idImgG);

        if(IE && document.body.clientHeight) hgt = document.body.clientHeight;
        else hgt = (IE)?document.documentElement.clientHeight:window.innerHeight;

        hgt = hgt / 2;

        if(IE && document.body.scrollTop) sclTop = document.body.scrollTop;
        else sclTop = (IE)?document.documentElement.scrollTop:window.pageYOffset;

        dMove.style.top = sclTop + hgt - (dImgG.height/2);

        if(IE && document.body.clientWidth) wdt = document.body.clientWidth;
        else wdt = (IE)?document.documentElement.clientWidth:window.innerWidth;

        wdt = wdt / 2;

        if((tempX) < wdt)
            dMove.style.left  = (tempX + 25) + "px";
        else
            dMove.style.left  = (tempX - 25 - (dImgG.width)) + "px";

        onDrag = true;
    } else {
        stopDrag(e, moveDiv);
        onDrag = false;
    }
 
}

function startDrag(e, div) {
    if(!onDrag) {
        var elMove = document.getElementById(div);

        if(elMove){
            elMove.style.display    = "block";
            elMove.style.visibility = "visible";
        }
    }
    return false;
}


function stopDrag(e, div) {
    var elMove = document.getElementById(div);

    if(elMove){
        elMove.style.display    = "none";
        elMove.style.visibility = "hidden";
    }

    return false;
}

document.onmousemove = getMouseXY;