$(document).ready(function(){
	$('#second_block').hide();
	$('.selector_link').click(function(){
		var clicked_id = $(this).attr('id');

		if (clicked_id == 'first_selector') {
			$('#first_block').fadeIn();
			$('#second_block').hide();
		} else if (clicked_id == 'second_selector') {
			$('#first_block').hide();
			$('#second_block').fadeIn();
		}
		
		return false;
	});
});