public void PopulateDiseaWiseGridView()
{
int diseaseId = Convert.ToInt32(diseaseDropDownList.SelectedValue);
string date1 = firstDateTextBox.Text;
string date2 = lastDateTextBox.Text;
diseaseWiseGridView.DataSource = manger.GetDiseaseWiseReport(diseaseId, date1, date2);
diseaseWiseGridView.DataBind();
}