Error in Use Dataset.tables[].clear() . Help Me

[hdv212]

hi my dataset contain 2 related tables and i want user click on datagrid cell in datagrid1 the table2's information show in datagrid2 (it is true work ).but i click the other cells of datagrid1 the dataset don't clear and show related information of previous row . when i clear dataset.tables["table2"].clear() the follwing error show me : Object reference not set to an instance of an object how to solve my problem ??(i want to show only information of current row)

[nps_ltv]

According to me, 2 DataTable objects are related, so you can not remove all rows of table2. Because table1's data is referencing to data of table2. NPS.