// 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 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 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;
    }
} // 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

/** add param to queryString, not encode the value**/
function addToQuery(queryString,param,value)
{
                if(param == null)
                  return ;
                  
                var sbQuery="";
                var items=queryString.split("&");
                for (var i = 0; i < items.length;i++) 
                {
                    var item = items[i];                       
                    //if the param has exist, skip
                    if(item.substring(0,param.length+1)==(param+"=")||item==param)
                    {
                        continue;
                    }
                    else
                    {
                        sbQuery += "&";
                        sbQuery += item; 
                    }
                }
                
                // append the new param at the end
                sbQuery +="&";
                sbQuery += param;
        	    sbQuery += "=";
        	    sbQuery += URLEncode(value);
        	    return sbQuery.substring(1,sbQuery.length);
}

function URLEncode(str) 
{     
    str = escape(str);       
     // JScript doesn't think '/' needs to be escaped...       
    // I'm not sure it does either, but take it out to be       
     // consistent with VBScript's built-in URLEncode()       
    while (str.indexOf("/")!=-1)      
     {            
         str = str.replace("/","%2F");   
       } 
    return str;   
 }