如何将文本框的值从aspx.cs页面发送到html

Question

private string returnSponserName() {
    try {
        string strRtn = "";
        string strQry = "";

        strQry = "SELECT MBR_NM  FROM MBR_MST WHERE MBR_ID='" + Request.Form["SponserId"].ToString() + "'";

        DataTable dt = new DataTable();
        dt = clsdt.getDataTable(strQry);
        if (dt.Rows.Count != 0) {

            strRtn = "|" + dt.Rows[0]["MBR_NM"].ToString() + "^";
        }
        return strRtn;
    }

上面是asp页面的部分代码。如何获取从asp页面返回到html页面的单个texbox的值。