The streets of Brighton and Hove have been filled this week with thousands of children enjoying their half-term holidays.

Also enjoying themselves in the autumn sunshine have been large numbers of men in suits sporting large lapel badges.

These badges indicate the men, and plenty of women too, are among the 17,000 who have been attending a big computer congress and exhibition on the seafront.

Apart from the Labour conference last month, it is the biggest regular event in the conference calendar.

It is worth millions of pounds to the city and is bringing benefits, direct and indirect, to many of the children and their families who have been sauntering in the sunshine.

Conferences have played a big role in the prosperity of Brighton for the last 40 years and should continue to do so.

You have only to look at the relative success of resorts which have embraced the conference trade to their civic bosoms and those which carried on regardless.

Eastbourne and Brighton are thriving with hundreds of hotels. Hastings, all too obviously, is not.

It was a brave decision by Brighton to forsake the bucket and spade trade at a time when it was diverting to Spain and concentrate on conferences instead.

Private enterprise in the form of Harold Poster's Metropole Hotel provided an early example of meeting and exhibition halls.

Even bolder was the move by councillors to build the Brighton Centre, which was the first tailor-made conference hall in the country.

Opened in 1977 by the then Prime Minister Jim Callaghan, it immediately gave the resort a head start over its rivals.

Its main hall capacity of 5,000 was the biggest in the country and for good measure it was able to stage spectaculars such as ice shows and pop concerts with the biggest names in the world.

It cost £10 million to build the centre.

The first £4 million came from land sales including a farm and the so-called golden acres off London Road.

The rest had to be raised from borrowing and for several years the big brutal building cost every man, woman and child in the town £10 per annum.

That was a big civic investment but it proved worthwhile. The centre has been responsible for an investment of many millions in Brighton each year, not just from the big political organisations such as Labour, which achieve plenty of publicity, but also from conferences such as the one there this week.

Now the city has a decision to make as big as those made in the Sixties and the Seventies.

It is to rebuild or replace the centre with a building that will keep Brighton ahead of the game for the next half-century.

Anyone visiting the centre now that it is 24 years old can see it is tired and out of date.

If nothing is done, conferences and other organisations will slowly slip away, not simply to Brighton's rivals in this country such as Bournemouth, but also to resorts in other countries and on other continents.

The new centre will have to be much larger to take the extra exhibition space.

It will have to be a great deal more flexible. It should be capable of staging all kinds of sport and leisure.

It needs to be an attractive landmark building rather than a dull concrete monolith.

Producing the political will to achieve this development will be one of the first major tests of the new system of working for the city council agreed in the referendum two weeks ago.

Of course there must be debate over what exactly should be provided there, but that should not obscure the need to build it.

It will need another large investment and some of it will have to come from the private as well as the public sector for the project to succeed.

Councillors could easily find scores of reasons not to go ahead with it but they should look at long-term gain rather than short-term popularity for the sake of all those children they see on the streets of Brighton this week.