private void BindCurrencyType()
    {
        DataTable dt = PurchaseOrderDBHelper.GetCurrenyType();

        if (dt != null && dt.Rows.Count > 0)
        {
            ddlCurrencyType.DataSource     = dt;
            ddlCurrencyType.DataTextField  = "CurrencyName";
            ddlCurrencyType.DataValueField = "hhh";
            ddlCurrencyType.DataBind();

            string aaa = ddlCurrencyType.Value;
            CurrencyTypeID.Value = aaa.Split('_')[0];
            txtExchangeRate.Text = aaa.Split('_')[1];
        }
    }