function event_obj(ajax_url)
{

    var self = this;
    // creates an ajax_class object and initiates the AJAX connection
    this.ajax_comm_with_server=function( event_id)
    {
        var params = self.ajax_params ;
        params.ajax_url = self.base_url + event_id ;
        params.extended_data = event_id ;
        var ajax = new ajax_class( params) ;
        ajax.comm_with_server() ;
    } ;


    // let the user know that we're making a connection by displaying an animated gif, this is called from the
    //   ajax js so you don't need to worry about when to call it
    this.ajax_display_processing_message=function( on_off)
    {
        // clear the ajax div contents
        if (on_off != 'off')
        {
            // need to reference global var instead of "this" b/c of scope issues
            self.update_ajax_div( '') ;
        }

        // hide/show the div containing the indicator as appropraite
        var style = (on_off == 'off') ? 'none' : '' ;
        if (document.getElementById)
        {
            document.getElementById("indicator").style.display = style ;
        }
        else
        {
            document.all.indicator.style.display = style ;
        }
    } ;


    // we'll be getting either an http.responseText or http.responseXML, whatever we specified.  Handle it here.
    this.ajax_success_handler=function( response)
    {
        // NOTE: this just means status was 200; there could still be an error

        // need to reference global var instead of "this" b/c of scope issues
        self.update_ajax_div( response) ;
    } ;


    // ajax returned an error, so deal with it gracefully
    this.ajax_failure_handler=function( message, error_code, ajax_request)
    {
        // case of a critical error, probably a developer goof
        if (error_code == 0)
        {
            detail_message = 'Error Details:\n ' + message ;
        }
        // response error from the server
        else
        {
            detail_message = 'Error Details:\n There was an http response error from the server, #' + error_code + ': "' + message + '"\n\n For full details, see:\n http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html';
        }

        // the message will have error details but also a link to the event they are looking for
    //	message = '<br/><br/><center>Event Data Unavailable.<br/><a href="javascript:alert(detail_message)" style="font-size:80%">Error Details</a><br/><br/><a href="/page/event/detail/' + ajax_request.extended_data + '">View Details of this Event</a></center>';
        message = '<div id="event_error"><p id="error_details"><span class="error_title">Event Data Unavailable.</span><a href="javascript:alert(detail_message)" style="font-size:80%">Error Details</a></p><p id="event_details"><a href="/page/event/detail/' + ajax_request.extended_data + '">View Details of this Event</a></p></div>' ;

        // need to reference global var instead of "this" b/c of scope issues
        self.update_ajax_div( message) ;
    } ;


    // a helper function that updates the ajax target div contents
    this.update_ajax_div=function( message)
    {
        if (document.getElementById)
        {
            document.getElementById("ajax").innerHTML = message ;
        }
        else
        {
            document.all.ajax.innerHTML = message ;
        }
    } ;


    // we have ajax, so breakout of the "noscript" fallback UI
    this.ajax_available_handler=function()
    {
        self.update_ajax_div( '<br/><br/>Loading Event Details...') ;
    } ;


    // if we have js but not ajax
    this.ajax_unavailable_handler=function()
    {
        // show noscript implementation

        // the fallback has already been setup, but we may have need to hide some divs in here
    } ;


    // if ajax is not enabled, implement our fallback strategy for linking... go to the page instead of ajax
    this.get_url=function( no_ajax_url, ajax_param, eventAjaxName)
    {
        // we have ajax, so the links will be an ajax update
        if (self.ajax_is_enabled)
        {
    //		return "window.event2.ajax_params.test_http_404=true;window.event2.ajax_comm_with_server('" + ajax_param + "');" ;
            return eventAjaxName + ".ajax_comm_with_server('" + ajax_param + "');" ;
        }
        // no ajax, so the link will go directly to the event page
        else
        {
            return "location.href='" + no_ajax_url + "';" ;
        }
    } ;


    // (not ajax related) helper function for writing out the event listings
    this.write_item_contents=function( url, name, description, div_class)
    {
        // we're trying to have clickable div; on IE these conflict with anchor link, so set that to void
        if ( self.ajax_is_enabled)
        {
            document.write( '<li class="' + div_class + '" onclick="' + url + '">' +
                    '<a href="javascript:void(0);">' + name + '</a>' +
                    '</li>') ;
        }
        // if there's no ajax, we need to forget the idea of clickable divs, and just do the normal URL
        else
        {
            document.write( '<li class="' + div_class + '">' +
                    '<a href="javascript:' + url + '">' + name + '</a>' +
                    '</li>') ;
        }
                
        // note: sadly the idea of a clickable div doesn't work very well in IE; the div is only clickable where the text is!?!
    } ;


    // now that the page is drawn, perform initial ajax call (or handle no ajax fallback measures)
    this.initial_load=function()
    {
        if ( self.ajax_is_enabled)
        {
            self.ajax_available_handler() ;

            // make the server request only if we have a default value
            if (self.default_id != '')
            {
                self.ajax_comm_with_server( self.default_id) ;
            }
            else
            {
                self.update_ajax_div("") ;
            }

        }
        else
        {
            self.ajax_unavailable_handler() ;
        }
    } ;

	this.ajax_params = {
			ajax_url : '',
			timeout : 5000,
			success_handler : this.ajax_success_handler,
			failure_handler : this.ajax_failure_handler,
			display_processing_message : this.ajax_display_processing_message
	//		ajax_debug : true,
	//		test_no_ajax : true
	//		test_timeout : true
	//		test_permission_denied : true
	//		test_http_404 : true
			} ;

	this.base_url = ajax_url ;
	this.default_id = '' ;

//	this.ajax_is_enabled = ajax_check_enabled({ajax_debug : true, test_no_ajax : true}) ;
	this.ajax_is_enabled = ajax_check_enabled() ;

} ;