London, May 12: World One-day champions Sri Lanka practised at Lord's for the first time today still uncertain about their line-up for the World Cup opener against England on Friday.``We are happy with our build-up although we are not certain yet of our team to play England,'' said team manager Duleep Mendis.Aravinda de Silva, who scored the match-winning century in the 1996 final against Australia, scored an unbeaten half-century against Leicestershire in the final warm-up match yesterday while Chaminda Vaas took four for 14.Vaas, a lively left-arm swing bowler, will be a vital component of the Sri Lankan attack, especially if England bat first on Friday in conditions expected to favour pace bowling.England had a work-out before the Sri Lankans today and, although they will not announce their team until the morning of the match, they fielded what was effectively their first choice team in an easy victory over Hampshire yesterday``The side here was as close as we can get, although at Lord's we might give ourselves the option of a spinner,'' said chairman of selectors David Graveney.Graveney confirmed that opener Nick Knight, who scored only 17 in three warm-up games, would probably retain his place.England are likely to omit off-spinner Robert Croft, seamer Angus Fraser, test vice-captain Nasser Hussain and all-rounder Vince Wells from their final XI.Ian Austin, who took two for eight from eight overs against Hampshire, has pressed his claims strongly in the past week and Fraser, England's most experienced and successful Test bowler, is not expecting to play on his home ground. Meanwhile, Colombo is getting ready for the mega event. Loads of good food and gallons of beer will be on offer on Friday when cricket-crazy Sri Lanka comes to a standstill to watch their team open its campaign to retain the World Cup.Offices are likely to close early and streets will be deserted when captain Arjuna Ranatunga steps out at the Lord's for the toss with his English counterpart Alec Stewart.The two have traded jibes in recent days over various issues, including the use of stump microphones, and a win in the opener against England would make Sri Lankans more than happy.Sri Lankans take their cricket seriously and for local companies the World Cup offers a good opportunity to increase their sales at a time when the economy is slowing.Companies are pumping in millions of rupees in advertising campaigns to entice middle-class consumers into buying their products by offering free tickets to the biggest cricket show.From televisions to car radios and even refrigerators, everything is available at a discount.For those who can afford it, hotels in Colombo are offering special deals on the days Sri Lanka play their matches. Book a room, get free beer and watch cricket in five-star comfort. Giant screens have suddenly sprouted across the city, in hotels, restaurants and shops, for people to watch the match while some discotheques plan to open in the afternoon.``Fill yourself with Kottu Roti (a Sri Lanka dish), hamburgers, sandwiches and many more from our special menu. One-for-one offer on beer to keep your spirits high,'' Colombo 2000 discotheque advertised. Even free air tickets are available to the lucky ones. Others will simply stay home.``I am going to have an open house. Drop in if you feel like. There will be others,'' said a businessman, who would probably spend the next one month lolling in front of his television.That obviously creates problems for business in the country.``Productivity suffers World Cup cramp,'' screamed a headline in the Sunday Times newspaper. ``There would be more work in offices - calculating statistics and figures of Sri Lankan performances - and less of anything else,'' it said.Sri Lanka has the highest number of holidays in the world, the newspaper said, adding that public sector employees enjoy 172 official holidays in the year. They also get 40 days of annual leave, which most of them take.The only advantage for employers probably is that the matches don't start until 3:00 p.m. (1430 IST), which means some work might get done in the mornings.