will be in amsterdam in july/august would like to take a day trip to rotterdam .i plan on taking a train of course is tourist area close to train station like cs is to amsterdam ? and will i be able to purchase smoke at coffee shops there ?any suggestion would be appreciated.thanks in advance

There is no RLD in Rotterdam.

Main source of entertainment is via clubs (evening obviously) or prives, of which there are a number within walkable distance of Centraal station albeit perhaps 2-3x as far as Amsterdam CS to the Wallen. If this is the main reason for you to visit then don't bother.

R'dam is good if you are a fan of concrete: the city centre is a real treat, especially the Lijnbaan. Currently there is a special display of Dutch builder's skills - the most fantastic "workers' palace" I have seen yet - next to the station. Whilst gawping at this, don't forget to watch out for trucks reversing across the pavement regardless of pedestrians.

The cliche' I was told was "go to Rotterdam to make money, go to Amsterdam to party, go to the Hague to sleep".

go to The Hague to sleep? Behave! Den Haag is a great party place!

Only during the summer.....