var prs = {

	init: function() {
	
		//current year
		prs.current_year = $$('.year')[0].innerHTML;
		
		//handlers
		$$('.year').each( function(elm) {
		
			elm.observe( 'click', function(e) { prs.select( elm.id.replace( /year_/, '' ) ) });
			elm.observe( 'mouseover', function(e) { prs.mouseover( elm.id.replace( /year_/, '' ) ) });
			elm.observe( 'mouseout', function(e) { prs.mouseout( elm.id.replace( /year_/, '' ) ) });
		
		});

		$$('.news-items').each( function(elm) {
		
			elm.observe( 'click', function(e) { prs.select( elm.id.replace( /prs_/, '' ) ) });
			elm.observe( 'mouseover', function(e) { prs.mouseover( elm.id.replace( /prs_/, '' ) ) });
			elm.observe( 'mouseout', function(e) { prs.mouseout( elm.id.replace( /prs_/, '' ) ) });
		
		});

			
	},

	select: function( year ) {
				
		$( 'year_' + year ).addClassName( 'year-selected' );
		$( 'year_' + prs.current_year ).removeClassName( 'year-selected' );

		$( 'prs_' + year ).addClassName( 'news-items-selected' );	
		$( 'prs_' + prs.current_year ).removeClassName( 'news-items-selected' );
	
		prs.current_year = year;
		
		prs.mouseout( year );
		
		new Effect.ScrollTo( 'prs_' + year );
	
	},

	mouseover: function( year ) {
		
		$( 'year_' + year ).addClassName( 'year-over' );
		$( 'prs_' + year ).addClassName( 'news-items-over' );	
	
	},
	
	mouseout: function( year ) {
				
		$( 'year_' + year ).removeClassName( 'year-over' );
		$( 'prs_' + year ).removeClassName( 'news-items-over' );	
	
	}

}

document.observe( 'dom:loaded', prs.init.bind(prs) );