var origin = 1;

function getDim(el) {
    for (var lx = 0,ly = 0; el != null;
         lx += el.offsetLeft,ly += el.offsetTop,el = el.offsetParent);
    return {x:lx,y:ly}
}

function checkvalid() {
    var sticky = document.getElementById('sticky');
    if (sticky) {
        if (navigator.appName == "Microsoft Internet Explorer") {
            sticky.style.visibility = 'visible';
            stick();
        }
        else {
            sticky.style.visibility = 'hidden';
        }
    }
}

function stick() {
    var mySpanDim = getDim(document.getElementById('sticky'));
    var mySpanDim_orig = getDim(document.getElementById('origin'));    
    var mySpanDim_tablebottom = getDim(document.getElementById('tablebottom'));

    var scrollTop = document.documentElement.scrollTop;
    //alert('scrollTop: ' + document.documentElement.scrollTop);
    //alert('sticky dim: ' + mySpanDim.x + ', ' + mySpanDim.y);

    if ((scrollTop > mySpanDim.y) || (origin == 0)) {
        document.getElementById("sticky").style.pixelTop = scrollTop;        
        origin = 0;
    }

    // return to the top if the view is the user scrolls back to top
    if (scrollTop < mySpanDim_orig.y) {
        document.getElementById("sticky").style.pixelTop = mySpanDim_orig.y;
        origin = 1;
    }
    
    if (scrollTop > (mySpanDim_tablebottom.y - 65)) {
        document.getElementById("sticky").style.pixelTop = (mySpanDim_tablebottom.y - 65);
        origin = 0;
    }
}