Data set event problem

Hello,

In my report there are 6 datasets.

In all these datasets srored procedure is used.And one parameter is passed to that.

My question is how can i handle the dataset for null parameter?

Means, i dont want to load the stored procedure if the parameter was not passed.

Because sometimes i have only one parameter for dataset-1, and remaining have no parameter passed.

So at that time my report loads all datasets and took so much time.

So i want script for dataset that i dont call procedure if parameter is null.