function getStyleObject(objectId)
{
    // cross-browser function to get an object's style object given its id
    if(document.getElementById && document.getElementById(objectId))
    {
	    // W3C DOM
	    return document.getElementById(objectId).style;
    }
    else if (document.all && document.all(objectId))
    {
	    // MSIE 4 DOM
	    return document.all(objectId).style;
    }
    else if (document.layers && document.layers[objectId])
    {
	    // NN 4 DOM.. note: this won't find nested layers
	    return document.layers[objectId];
    }
    else
    {
	    return false;
    }
}

function changeObjectVisibility(objectId, newVisibility)
{
    // get a reference to the cross-browser style object and make sure the object exists
    var styleObject = getStyleObject(objectId);
    
    if (styleObject)
    {
    	styleObject.visibility = newVisibility;
    	return true;
    }
    else
    {
    	// we couldn't find the object, so we can't change its visibility
    	return false;
    }
}

function moveObject(objectId, newXCoordinate, newYCoordinate)
{
    // get a reference to the cross-browser style object and make sure the object exists
    var styleObject = getStyleObject(objectId);
 
    if (styleObject)
    {
	    styleObject.left = newXCoordinate + "px";
	    styleObject.top = newYCoordinate + "px";
	    return true;
    }
    else
    {
	    // we couldn't find the object, so we can't very well move it
	    return false;
    }
}