Updating data in Ms-Access via asp.net and C#, gett System.Data.OleDb.OleDbException: No value given for one or more required parameters -

i trying update data asp.net form. have gridview, when click on particular row in grid view displays data respective texboxes. want update data. tried write query showed me error. here full code of c#,

using system; using system.collections; using system.configuration; using system.data; using system.linq; using system.web; using system.web.security; using system.web.ui; using system.web.ui.htmlcontrols; using system.web.ui.webcontrols; using system.web.ui.webcontrols.webparts; using system.xml.linq; using system.data.oledb; using system.data.sqlclient;  public partial class company_master : system.web.ui.page {     protected void page_load(object sender, eventargs e)     {         if (!ispostback)         {             lbluser.text = session["user_id"].tostring();             lbldiv.text = session["division_id"].tostring();             lblunit.text = session["unitcode"].tostring();             lblloyr.text = session["year"].tostring();             lbldate.text = session["date"].tostring();         }          util.jqueryutils.registertextboxfordatepicker(page, txtregdt);         datatable dt;         oledbconnection conn = new oledbconnection(configurationmanager.connectionstrings["vhgroupconnection"].connectionstring);         oledbcommand cmd1 = new oledbcommand("select cmp_id,cmp_name,reg_no,reg_dt,addr_line_1,addr_line_2,addr_line_3,pin_code,lst_no,cst_no,fax,phone,emailid company_master order cmp_id asc", conn);         oledbdataadapter da = new oledbdataadapter(cmd1);         dt = new datatable();         da.fill(dt);         gridview1.datasource = dt;         gridview1.databind();         session["comp"] = dt;         gridview1.visible = true;      }     protected void btnadd_click(object sender, eventargs e)     {         try         {             oledbconnection myconnection = new oledbconnection(configurationmanager.connectionstrings["vhgroupconnection"].connectionstring);             string query = "insert company_master(cmp_id,cmp_name,reg_no,reg_dt,addr_line_1,addr_line_2,addr_line_3,pin_code,lst_no,cst_no,fax,phone,emailid) values(?,?,?,?,?,?,?,?,?,?,?,?,?)";             using (myconnection)             {                 myconnection.open();                 using (oledbcommand cmd = new oledbcommand(query, myconnection))                 {                     cmd.commandtype = commandtype.text;                     cmd.parameters.addwithvalue("cmp_id", txtcompid.text);                     cmd.parameters.addwithvalue("cmp_name", txtcompname.text);                     cmd.parameters.addwithvalue("reg_no", txtregno.text);                     cmd.parameters.addwithvalue("reg_dt", dateformat.splitdatestringandreturnobject(txtregdt.text));                     cmd.parameters.addwithvalue("addr_line_1", txtaddr.text);                     cmd.parameters.addwithvalue("addr_line_2", txtaddr1.text);                     cmd.parameters.addwithvalue("addr_line_3", txtaddr2.text);                     cmd.parameters.addwithvalue("pin_code" ,txtpin.text);                     cmd.parameters.addwithvalue("lst_no",txtlocalsale.text);                     cmd.parameters.addwithvalue("cst_no",txtcentraltxt.text);                     cmd.parameters.addwithvalue("fax", txtfax.text);                     cmd.parameters.addwithvalue("phone", txtphone.text);                     cmd.parameters.addwithvalue("emailid", txtemail.text);                      cmd.executenonquery();                 }                 myconnection.close();             }          }         catch (exception ex)         {             response.write("error in application :" + ex.stacktrace + ex.message);         }     }      private class dateformat     {         public static datetime splitdatestringandreturnobject(string datestring)         {             if (datestring == "" || datestring == null)             {                  int year = 9999;                 int month = 1;                 int day = 1;                 datetime dtobj = new datetime(year, month, day);                 return dtobj;             }             else             {                 int len;                 string[] datesplit = datestring.split('-');                 len = datesplit.length;                 if (len < 3)                 {                     datesplit = datestring.split('/');                 }                  int year = convert.toint32(datesplit[2]);                 int month = convert.toint32(datesplit[1]);                 int day = convert.toint32(datesplit[0]);                 datetime dtobj = new datetime(year, month, day);                 return dtobj;             }          }     }      protected void gridview1_selectedindexchanged(object sender, eventargs e)     {         txtcompid.text = gridview1.selecteddatakey.values[0].tostring();         txtcompname.text = gridview1.selecteddatakey.values[1].tostring();         txtregno.text = gridview1.selecteddatakey.values[2].tostring();         txtregdt.text = gridview1.selecteddatakey.values[3].tostring();         txtaddr.text = gridview1.selecteddatakey.values[4].tostring();         txtaddr1.text = gridview1.selecteddatakey.values[5].tostring();         txtaddr2.text = gridview1.selecteddatakey.values[6].tostring();         txtpin.text = gridview1.selecteddatakey.values[7].tostring();         txtlocalsale.text = gridview1.selecteddatakey.values[8].tostring();         txtcentraltxt.text = gridview1.selecteddatakey.values[9].tostring();         txtfax.text = gridview1.selecteddatakey.values[10].tostring();         txtphone.text = gridview1.selecteddatakey.values[11].tostring();         txtemail.text = gridview1.selecteddatakey.values[12].tostring();     }     protected void btnupdate_click(object sender, eventargs e)     {     try     {   **oledbconnection con = new oledbconnection(configurationmanager.connectionstrings["vhgroupconnection"].connectionstring);             oledbcommand cmd = new oledbcommand("update company_master set cmp_name = '" + txtcompname.text + "',reg_no = '" + txtregno.text + "',reg_dt ='" + dateformat.splitdatestringandreturnobject(txtregdt.text) + "',addr_line_1 = '" + txtaddr.text + "',addr_line_2 = '" + txtaddr1.text + "',addr_line_3 = '" + txtaddr2.text + "',pin_code = '" + txtpin.text + "',lst_no = '" + txtlocalsale.text + "',cst_no ='" + txtcentraltxt.text + "',phone = '" + txtphone.text + "',email ='" + txtemail.text + "' cmp_id ='" + txtcompid.text + "'", con);             con.open();             cmd.commandtype = commandtype.text;             oledbdataadapter da = new oledbdataadapter(cmd);             cmd.commandtype = commandtype.text;              cmd.executenonquery();             response.write("update success");             con.close();**         }         catch (exception ex)         {             response.write(ex.tostring());         }          }   } 

please me write query.

after updating gridvew should updated.