function moveSquare(left, top) {
    var navSquare = window.document.getElementById('navSquare');
    navSquare.style.display = 'block';
    navSquare.style.position = 'absolute';
    navSquare.style.top = top + 'px';
    navSquare.style.left = left + 'px';
}

function removeSquare() {
    var navSquare = window.document.getElementById('navSquare');
    navSquare.style.display = 'none';
}

function showHighlight(imageId) {
    var theImage = window.document.getElementById(imageId);
    theImage.style.border = '2px solid red';
}

function removeHighlight(imageId) {
    var theImage = window.document.getElementById(imageId);
    theImage.style.border = '2px solid black';
}