function openPopup(id) {
    var pu = document.getElementById(id)
    if (pu != undefined) {
        pu.style.top = popTop;
        pu.style.left = popLeft;
        pu.style.visibility = 'visible';
    }
}

function closePopup(id) {
    var pu = document.getElementById(id)
    if (pu != undefined) {
        pu.style.visibility = 'hidden';
    }
}

var popTop = 0;
var popLeft = 0;

function get_mouse(e) {
    if (document.all) {  // IE
        popTop = 15 + event.clientY + document.body.scrollTop;
        popLeft = 20 + event.clientX + document.body.scrollLeft;
    } else {
        popTop = 15 + e.pageY;
        popLeft = 20 + e.pageX;
    }
}


document.onmousemove=get_mouse;