ERROR 1064 (42000) with triggers

[mahmoud ahmadinejad]

Hello

I have a table named country

in this table there is the columns name, capital, code, old_capital, datechanged

i have to make a trigger that will add to old_capital the old name of the capital, and in datechanged the date when the modification happened

I have made this trigger:
delimiter |

CREATE TRIGGER change_capital before UPDATE ON country
FOR each ROW
begin
INSERT INTO country (anciennecap) VALUES (OLD.Capital);
INSERT INTO country (datechange) VALUES (NOW());
end|


but it shows me the error:
ERROR 1442 (HY000): Can't update table 'country' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.

I do not understand my mistake. Can anyone help me out?

Thank you