var current_region;

function change_region ( sent_region )
{
	
	var region_name = '#' + sent_region;
	
	if ( region_name != current_region )
	{
		
		// hide all sub items
		$( '#north_america_sub' ).css( { display: 'none' } );
		$( '#europe_sub' ).css( { display: 'none' } );
		$( '#asia_pacific_sub' ).css( { display: 'none' } );
		$( '#portal_ad' ).css( { opacity: '0.15' } );
		
		// show selected region
		//$( region_name ).css( { display: 'block', opacity: '0' } );
		//$( region_name ).animate( { opacity: '1' }, 500 );
		$( region_name ).css( { display: 'block', opacity: '1' } );
		
		// set current region
		current_region = region_name;
		
	}
	
}