function Navigation ( data, activitiesElement, enterprisesElement, activitiesChooseText, enterprisesChooseText, actionUrl ) {
	
	this.data = [];
	this.activitiesElement = null;
	this.enterprisesElement = null;
	this.activitiesChooseText = '';
	this.enterprisesChooseText = '';
	this.actionUrl = '';

	this.constructor = function ( data, activitiesElement, enterprisesElement, activitiesChooseText, enterprisesChooseText, actionUrl ) {
		
		this.data = data;
		this.activitiesElement = activitiesElement;
		this.enterprisesElement = enterprisesElement;
		this.activitiesChooseText = activitiesChooseText;
		this.enterprisesChooseText = enterprisesChooseText;
		this.actionUrl = actionUrl;

		this.initiateActivities();
		this.initiateEnterprises();

		this.loadActivities();
		this.onActivitiesChange();

	}

	this.initiateActivities = function (  ) {

		this.activitiesElement.options[this.activitiesElement.options.length] = new Option(this.activitiesChooseText, 0);

	}

	this.initiateEnterprises = function (  ) {

		this.enterprisesElement.length = 0;
		this.enterprisesElement.options[this.enterprisesElement.options.length] = new Option(this.enterprisesChooseText, 0);

	}

	this.loadActivities = function (  ) {
		
		var activityId;
		for ( activityId in activities ) {
			
			var activityTitle = activities[activityId]['title'];
			this.activitiesElement.options[this.activitiesElement.options.length] = new Option(activityTitle, activityId);

		} // for
		
	}

	this.onActivitiesChange = function (  ) {
		
		this.initiateEnterprises();

		if ( this.activitiesElement.value == 0 ) { // get all enterprises

			var enterprises = new Array();
			
			for ( var activityId in this.data ) {

				for ( var enterpriseId in this.data[activityId].enterprises ) {

					enterprises[enterpriseId] = this.data[activityId].enterprises[enterpriseId];

				} // for

			} // for
			
		} else {
			
			var enterprises = this.data[this.activitiesElement.value].enterprises;
		
            document.getElementById('arrow').style.display = '';
		} // else

		var enterpriseId;

        var count = 0;
        
		for ( enterpriseId in enterprises ) {
			
			var enterpriseTitle = enterprises[enterpriseId]['title'];
			this.enterprisesElement.options[this.enterprisesElement.options.length] = new Option(enterpriseTitle, enterpriseId);
            
            count++;
		}

        /**
         *  Rusiuojame imoniu sarasa
         */ 		
        var enterpriseIds    = new Array();
        var enterpriseTitles = new Array();
        
        for(var i = 1; i < this.enterprisesElement.length; i++)
        {
            enterpriseTitles[i - 1] = this.enterprisesElement.options[i].text;
            enterpriseIds[this.enterprisesElement.options[i].text] = this.enterprisesElement.options[i].value;
        }
        
        enterpriseTitles.sort();
        
        for(var i = 1; i < this.enterprisesElement.length; i++)
        {
            this.enterprisesElement.options[i].text  = enterpriseTitles[i - 1];
            this.enterprisesElement.options[i].value = enterpriseIds[enterpriseTitles[i - 1]];
        }
		
		/**
		 *    Jeigu pasirinkta veikla uzsiima tik viena imone, mes is karto
		 *    redirect'iname i ja		 
		 */         		
		if(count == 1)
        {
            top.location.href = this.actionUrl+enterpriseId;
        }
		
	}

	this.onEnterprisesChange = function (  ) {

		if ( this.enterprisesElement.value == 0 ) { return; }
		
		top.location.href = this.actionUrl+this.enterprisesElement.value;

	}

	this.constructor(data, activitiesElement, enterprisesElement, activitiesChooseText, enterprisesChooseText, actionUrl);
	
}


function showArrow() {
	arrow = document.getElementById('arrow');
	arrow.style.visibility = 'visible';
}