Appellants are engaged in the business of marketing medicinal and pharmaceutical preparations. The first appellant is the registered proprietor of the Trade mark 'EMULGEL' in India which stands registered in its name with effect from 4.11.1987. Pursuant to the licence granted by the first appellant, the second appellant is manufacturing and marketing medicines under the Trade Mark 'EMULGEL' in India. The appellants claimed that they have acquired a common law right in the said trade mark 'EMULGEL'. In and around November, 1992, they came to know that the respondent is manufacturing and marketing a product called 'EMUGEL'. On 4.11.1992, the appellants caused a letter to be issued to the respondent to cease and desist from using the trade mark 'EMUGEL'. In their letter dated 12.11.1992 the respondent repudiated the claim of the appellants. A further letter was sent to the respondent on 2.7.1993. Thereafter, in his letter dated 7.7.1993 the respondent assured the appellant that he would stop using the name 'EMUGEL' and switch over to an alternative brand name. However, the alternative brand name he adopted is 'EUGEL' by which he has only dropped the letter M from the expre