Is committing
suicide legal?
In most countries, it isn't. It is against the law to
take one's life, or the
attempt to do so. So if you
fail to commit suicide and get arrested, technically you could get
prosecuted for attempting
murder.
If you get arrested, don't worry about going to
jail (at least, not in most civilized countries), because you will be declared
insane, and therefor probably be sent to a
mental institution.