// Copyright © 2000 by Apple Computer, Inc., All Rights Reserved.
//
// You may incorporate this Apple sample code into your own code
// without restriction. This Apple sample code has been provided "AS IS"
// and the responsibility for its operation is yours. You may redistribute
// this code, but you are not permitted to redistribute it as
// "Apple sample code" after having made changes.
//
// ************************
// layer utility routines *
// ************************

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

function MM_getObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

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;
    }
} // getStyleObject

function hideObject(objectId) {
    if(objectId) {
		//	return changeObjectVisibility(objectId, 'hidden');
	return changeObjectVisibility(objectId, 'none');
    } else {
    	return false;
    }
}

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

    } else {
    	return false;
    }
}

function switchObjectVisibility(objectId, cond) {
    if(cond)
    	showObject(objectId);
    else
    	hideObject(objectId);

}

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;
	styleObject.display = newVisibility;
	return true;
    } else {
	// we couldn't find the object, so we can't change its visibility
	return false;
    }
} // changeObjectVisibility

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;
	styleObject.top = newYCoordinate;
	return true;
    } else {
	// we couldn't find the object, so we can't very well move it
	return false;
    }
} // moveObject