Section 404 - Effect of previous convictions under section 401, 402 or 403.

Whoever is convicted of an offence under section 401,402 or 403 of this Penal Code shall, if he is shown to have been convicted of an offence under any of those sections within the previous six months, be punished-

(a) with imprisonment or fine which may extend to twice the maximum imprisonment or maximum fine prescribed for the offence of which he is convicted; and

(b) if he is shown to have been convicted of two or more such offences within the like period, then with imprisonment or fine which may extend to three times the maximum imprisonment or maximum fine aforesaid or with both.