Passing parameters from main report to table's datasource in iReport?

1. create required parameters in the main report by right clicking on the parameters section of main report------> add parameter-------->set the properties (data type) of newly added parameter to your desired one.
2. create equivalent parameters in the table/List's data source's parameters section exactly as in step 1.
3. from report explorer, right click on the table and click on Edit Table DataSet ------> Select the parameters tab ----------->Click on add ---------->Choose the parameter (which you created in the dataset's parameter section in step 2.) from upper combo (i.e. Dataset parameter name) ------> then click on lower button (i.e.) assign value expression i.e. the params which you added in step 1.

Now, you're done. The params(defined in scope of main report's parameter section) will be prompted to user at the report run-time and passed to the table's dataset's parameter which will be reflected in the table finally.
NOTE: We can add the params as in step 2. above into the table's dataSets scope with their properties "use as a prompt" checked (for the sake them to be prompted at the runtime to user), but they won't be prompted and we'll have to stay frustrated ; DON't use this approach.