Police are continuing the search for a man who allegedly smashed a bottle over the head of a 21-year-old at the Harp Hotel on Saturday.The victim, from Gerringong, needed stitches to his left hand after he was injured while trying to protect himself.The incident prompted renewed calls for the introduction of beer and alcopops in plastic bottles for late night venues.Illawarra Licensing Sergeant Gary Keevers, who waged a two-year campaign to have the industry warm to plastic cups in his command, said the introduction of plastic bottles was a more difficult battle.Saturday's alleged glassing occurred at 1.45am when a 21-year-old became involved in an argument with an unknown man inside the hotel.Police said the offender fled the scene despite attempts by security staff to catch him. The dog unit also searched for the offender without success. The injured man was treated at Wollongong Hospital for deep lacerations to his hand.Wollongong nightspots The Glasshouse Tavern and Cooneys introduced plastic cups in November 2007.It followed a number of glassings, including that of 20-year-old Krystle Kelley, who was blinded in her right eye after a glass was smashed in her face at The Glasshouse Tavern the same month.In December, police began enforcing new licensing laws on The Glasshouse Tavern including plastic cups after midnight after it was named as one of 48 NSW licensed venues singled out by Premier Nathan Rees as the most violent.Under the laws, alcohol such as alcopops and boutique beers that are supplied in glass bottles must first be poured into plastic cups for patrons. This law also applies to major sporting venues.Sgt Keevers said the alternative was to have the NSW Government legislate for alcohol companies to also supply their products in plastic bottles."We have been discussing this problem for the past 12 months," he said. "It's a hard problem to solve because we have so many different lines of alcohol in glass that are popular."A couple of years ago Carlton United Breweries brought out a line of Carlton Cold that you could actually buy in plastic bottles ... but for some reason it died off."Anyone who witnessed the incident or has information can call Wollongong police or Crime Stoppers on 1800 333 000.