/** need to do the following:
    1.  DONE - Close the open layer popup when a new one is selected.
    2.  Move an open layer appropriately when window is resized.
    3.  Get rid of the 'ghost window'
 */

var hide  = true;
var oldObj = 0;
var displayedLayer = 0;

/** this is the function called initially...
    */
function showHide(obj, hiddenLayerID) {
    if (!hide && (oldObj != obj) && (displayedLayer != hiddenLayerID)) {
        cleanUp(oldObj, displayedLayer);
    }
    oldObj = obj;
    displayedLayer = hiddenLayerID;
    var x = document.getElementById(hiddenLayerID);/*get layer*/
    
    hide = !hide;/*switch visibility*/
    x.style.visibility = (hide) ? 'hidden' : 'visible';
    setLayer(obj,hiddenLayerID);
}

/**calls to findPos() to set the position of the popup layer  */
function setLayer(obj,layer) {
    var coordinates = findPos(obj);
    coordinates[1] -= 0;
    var x = document.getElementById(layer);
    x.style.top = coordinates[1] + 'px';
    x.style.left = coordinates[0] + 'px';
}

/** recursively finds the parent's position relative to the document*/
function findPos(obj) {
    var curleft = 0;
    var curtop = 0;
    if (obj.offsetParent) {
        curleft = obj.offsetLeft;
        curtop = obj.offsetTop;
        while (obj = obj.offsetParent) {
            curleft += obj.offsetLeft;
            curtop += obj.offsetTop;
        }
    }
    return [curleft,curtop];
}

/**a function to check to see if there are any other windows open on this layer and close them (before opening a new one */
function cleanUp(oldObject, dispLayer) {
    showHide(oldObject, dispLayer);
}