How to get a collection of selected cells in datagridview

Question

My code currently allows a user to select an item at ago from a list of items in datagrid view.

I would want to change it so that it allows the user to select more than one item to be processed. i.e it now allows user to generate a report for one selected employee but i want to change that so that a user can generate more than one employee`s report at once

Here is my current source code

private void dgvPrintEmp_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
    {
            //added
      this.Clear_PrintEmp();
      if (e.RowIndex < 0)
        return;
      this.mStudId = Convert.ToInt32(this.dgvPrintEmp.Rows[e.RowIndex].Cells["empid_PrintEmp"].FormattedValue);
      this.lblEmpPrintEmp.Text = this.dgvPrintEmp.Rows[e.RowIndex].Cells["Empname_PrintEmp"].FormattedValue.ToString();
      this.btnPrintEmp.Enabled = true;
    }