In my project, i am executing some queries for selected records(rows). Once the query completes i want to uncheck all the records. Please help me to complete my functionality. Here is the code i used to uncheck. But it is not working.

public void UncheckDataRow()
{
for (int j = 0; j < gridTrade.Rows.Count; j++)
{
GridRecord selectedRow = gridTrade.Rows[j];
int columnIndex = gridTrade.Columns["Checked"].Index;
selectedRow.Items[columnIndex].Value = false;
}
}