//------------------------------------------------------------------------------
// XML HTTP REQUEST
//------------------------------------------------------------------------------
// Supports Safari, Mozilla 1.3+ (Firefox, etc) and IE 5.5+
//------------------------------------------------------------------------------


var use_enhanced_js = true;

try
{
    if ( ! use_charset )
    {
        var use_charset = '';
    }
}
catch( e ) { }

/*--------------------------------------------*/
// New object
/*--------------------------------------------*/

function ajax_request()
{
    this.isIE               = false;
    this.allow_use          = use_enhanced_js ? true : false;
    this.xmlhandler         = null;
    this.error_string       = '';
    this.nocache            = true;
    this.do_request_functon = function() {}
    this.loading_fired        = 0;
    this.centerdiv          = null;
}

/*--------------------------------------------*/
// Initiate
/*--------------------------------------------*/

ajax_request.prototype.xml_init = function()
{
    try
    {
        //------------------------------------------------
        // Moz, Safari, Opera
        //------------------------------------------------
        
        this.xmlhandler = new XMLHttpRequest();
        this.ie        = false;
        this.allow_use = true;
        return true;
    }
    catch(e)
    {
        try
        {
            //------------------------------------------------
            // IE
            //------------------------------------------------

            this.xmlhandler = new ActiveXObject('Microsoft.XMLHTTP');
            this.ie        = true;
            this.allow_use = true;
            return true;
        }
        catch(e)
        {
            this.ie        = true;
            this.allow_use = false;
            return false;
        }
    }
}

/*--------------------------------------------*/
// Actually send data
/*--------------------------------------------*/

ajax_request.prototype.process = function( url, type, post )
{
    //------------------------------------------------
    // The 'post' variable needs to be in the following format:
    //
    // var=content&var2=content&var3=content
    //
    // All values need to be escaped with encodeURIComponent();
    //------------------------------------------------
    
    type = type == "POST" ? "POST" : "GET";
    
    //------------------------------------------------
    // Use nocache where possible...
    //------------------------------------------------
    
    if ( this.nocache == true  && type == 'GET' )
    {
        url = this.nocache_url( url );
    }
    
    //------------------------------------------------
    // Make sure we're initialized
    //------------------------------------------------
    
    if ( ! this.xmlhandler )
    {
        this.xml_init();
    }
    
    //------------------------------------------------
    // Only go when ready
    //------------------------------------------------
    
    if ( ! this.readystate_not_ready() )
    {
        this.xmlhandler.open(type, url, true);
        
        if ( type == "GET" )
        {
            this.xmlhandler.send(null);
        }
        else
        {
            if ( typeof( this.xmlhandler.setRequestHeader ) != "undefined" )
            {
                this.xmlhandler.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=' + use_charset);
            }
            
            this.xmlhandler.send( post );
        }
        
        if ( this.xmlhandler.readyState == 4 && this.xmlhandler.status == 200 )
        {
            return true;
        }
    }
    
    return false;
}

/*--------------------------------------------*/
// retrieve text of an XML document element, including
// elements using namespaces
/*--------------------------------------------*/

ajax_request.prototype.get_element_text_ns = function(prefix, local, parentElem, index)
{
    var result = "";
    
    if ( prefix && this.isIE )
    {
        //-------------------------------
        // IE
        //-------------------------------
        
        result = parentElem.getElementsByTagName(prefix + ":" + local)[index];
    }
    else
    {
        //-------------------------------
        // Safari, Gecko
        //-------------------------------
        
        result = parentElem.getElementsByTagName(local)[index];
    }
    
    if ( result )
    {
        if (result.childNodes.length > 1)
        {
            return result.childNodes[1].nodeValue;
        }
        else
        {
            return result.firstChild.nodeValue;            
        }
    }
    else
    {
        return "n/a";
    }
}

/*--------------------------------------------*/
// Make sure URL is not cached
/*--------------------------------------------*/

ajax_request.prototype.nocache_url = function (url)
{
    var sep    = ( -1 < url.indexOf("?") ) ? "&" : "?";
    var mydate = new Date();
    var newurl = url + sep + "__=" + mydate.getTime();
    return newurl;
}

/*--------------------------------------------*/
// Takes an array of:
// array[ field ] = value
// and returns a nice encoded POST string
/*--------------------------------------------*/

ajax_request.prototype.format_for_post = function( arrayfields )
{
    var str = '';
    
    try
    {
        for( var i in arrayfields )
        {
            str += i + '=' + this.encodeurl(arrayfields[i]) + '&';
        }
    }
    catch(e)
    {
    }
    
    return str;
}

/*--------------------------------------------*/
// Hand roll encode URL to UTF-8
/*--------------------------------------------*/

ajax_request.prototype.encodeurl = function( url )
{
    //-------------------------------
    // Ensure we have a string
    //-------------------------------
    
    url = url.toString();

    var regcheck = url.match(/[\x90-\xFF]/g);
    
    if ( regcheck )
    {
        for (var i = 0; i < i.length; i++)
        {
            url = url.replace(regcheck[i], '%u00' + (regcheck[i].charCodeAt(0) & 0xFF).toString(16).toUpperCase());
        }
    }

    return escape(url).replace(/\+/g, "%2B");
}


/*--------------------------------------------*/
// Check to ensure ready state-ness
/*--------------------------------------------*/

ajax_request.prototype.readystate_not_ready = function()
{
    return ( this.xmlhandler.readyState && ( this.xmlhandler.readyState < 4 ) );
}

/*--------------------------------------------*/
// Check to ensure ready state-ness
/*--------------------------------------------*/

ajax_request.prototype.readystate_ready_and_ok = function()
{
    return ( this.xmlhandler.readyState == 4 && this.xmlhandler.status == 200 ) ? true : false;
}

/*--------------------------------------------*/
// Onready state change event handler
/*--------------------------------------------*/

ajax_request.prototype.onreadystatechange = function( event )
{
    //------------------------------------------------
    // Make sure we're initialized
    //------------------------------------------------
    
    if ( ! this.xmlhandler )
    {
        this.xml_init();
    }
    
    //------------------------------------------------
    // Make sure its a function event
    //------------------------------------------------
    
    if ( typeof(event) == 'function' )
    {
        this.xmlhandler.onreadystatechange = event;
    }
}

/*--------------------------------------------*/
// Show loading layer
/*--------------------------------------------*/

ajax_request.prototype.show_loading = function( message )
{
    if ( ! this.loading_fired )
    {
        this.loading_fired = 1;
        
        //------------------------------------------------
        // Change text?
        //------------------------------------------------
        
        if ( message )
        {
            document.getElementById( 'loading-layer-text' ).innerHTML = message;
        }
        
        this.centerdiv         = new center_div();
        this.centerdiv.divname = 'loading-layer';
        this.centerdiv.move_div();
    }
    
    return;
}

/*--------------------------------------------*/
// Hide loading layer
/*--------------------------------------------*/

ajax_request.prototype.hide_loading = function()
{
    try
    {
        if ( this.centerdiv && this.centerdiv.divobj )
        {
            this.centerdiv.hide_div();
        }
    }
    catch(e)
    {
    }
    
    this.loading_fired = 0;
    
    return;
}

/*--------------------------------------------*/
// IPB thinks we can use fancy JS, lets see...
/*--------------------------------------------*/

if ( use_enhanced_js )
{
    use_enhanced_js = ajax_request.prototype.xml_init() ? 1 : 0;
}