What are the requirements to make a Will?
You must be at least 21 years of age and be of sound mind before you can make a will. The will itself:-
* must be in English;
* must be in writing; and
* must be signed by you in the presence of 2 witnesses who also sign in the presence of one another (your beneficiaries and their respective spouses should not be witnesses).
If you are a soldier in actual military service or a seaman at sea, you may make a will even if you are below 21 years old. If any of the beneficiaries are minors (ie below the age of 21 years), there must be a least 2 trustees/executors.
Excerpt taken from here
Yeah, so dont be silly n just think that by say saying happily, your will (or testament) will be recognize by the law.