NS4 = (document.layers);
IE4 = (document.all); 
ver4 = (NS4 || IE4);

document.onmousemove = mouseMove;
document.onmouseup = mouseUp;

var dragObject = null;
var mouseOffset = null;

function getMouseOffset(target, ev) {
    ev = ev || window.event;

    var docPos = getPosition(target);
    var mousePos = mouseCoords(ev);
    return { x: mousePos.x - docPos.x, y: mousePos.y - docPos.y };
}

function getPosition(e) {
    var left = 0;
    var top = 0;

    while (e.offsetParent) {
        left += e.offsetLeft;
        top += e.offsetTop;
        e = e.offsetParent;
    }

    left += e.offsetLeft;
    top += e.offsetTop;

    return { x: left, y: top };
}

function mouseMove(ev) {
    ev = ev || window.event;
    var mousePos = mouseCoords(ev);

    if (dragObject) {
        dragObject.style.position = 'absolute';
        dragObject.style.top = mousePos.y - mouseOffset.y;
        dragObject.style.left = mousePos.x - mouseOffset.x;

        return false;
    }
}

function mouseUp() {
    dragObject = null;
}

function makeDraggable(item) {
    if (!item) return;
    item.onmousedown = function(ev) {
        dragObject = this;
        mouseOffset = getMouseOffset(this, ev);
        return false;
    }
}

function mouseCoords(ev) {
    if (ev.pageX || ev.pageY) {
        return { x: ev.pageX, y: ev.pageY };
    } else try { 
        return {
            x: ev.clientX + document.body.scrollLeft - document.body.clientLeft,
            y: ev.clientY + document.body.scrollTop - document.body.clientTop
        }   
    } catch(e) {}
}