var lastShown = null;

function ShowRootLineContent(elementname, caller) {
    if (lastShown != null) {
        lastShown.style.display = "none";
        lastShown = null;
    }
    var dstElmnt = document.getElementById( elementname );
    if (dstElmnt!=null && dstElmnt!='undefined') {
        dstElmnt.style.display = "block";
        dstElmnt.style.left = caller.offsetLeft + caller.width + "px";
        dstElmnt.style.top = caller.offsetTop + caller.height + "px";
        lastShown = dstElmnt;
    }
    else {
        // not found ?!?
    }
}