function addBookToMarket(field_id, field_seller_id, field_price, field_condition) {
	
	var bm_b_id = $('#'+field_id).val();
	var bm_seller_id = $('#'+field_seller_id).val();
	var bm_price = $('#'+field_price).val()+'.'+$('#'+field_price+'_cent').val();
	var bm_condition = $('input[@name='+field_condition+']:checked').val();
	$.post("includes/add_book_to_market.php", { bm_b_id: bm_b_id, bm_seller_id: bm_seller_id, bm_price: bm_price, bm_condition: bm_condition }, 
		function(data) { 
			if (data == 1) {
				$('#add_book_to_market_feedback').show();
			} else
				alert('hier stimmt was nicht.');
	});	
}