This code useful for u.. firstly add tag in web config
After then
Pro = ConfigurationManager.AppSettings["ConnectionStrings"].ToString();
MyPath = ConfigurationManager.AppSettings["dbfile"].ToString();
Conns = String.Format(Pro, HttpContext.Current.Server.MapPath(MyPath));
con = new OleDbConnection(Conns);
con.Open();
string st = "Madhaya Pradesh";
string qql = "INSERT into Registration(UniqueID,Name,FName,DOB,TMarks,OMarks,PMarks,PClass,PLine,Board,District,Division,Category,Sex,PChallange,Address,Pin,RDistrict,State,Phone,SchoolAddress,SchoolPincode,SchoolDistrict) values('" + lbluniquid.Text + "','" + txtname.Text + "','" + txtfathername.Text + "','" + tbMyDate.Text + "'," + txttotalmarks.Text + "," + txtobtainmarks.Text + "," + p + ",'" + rdpresent.SelectedItem.Text + "','" + rdpovertyline.SelectedItem.Text + "','" + rdboard.SelectedItem.Text + "','" + ddldistrict.SelectedItem.Text + "','" + lbldivision.Text + "','" + rdcategory.SelectedItem.Text + "','" + rdsex.SelectedItem.Text + "','" + rdphysically.SelectedItem.Text + "','" + txtaddress.Text + "','" + txtpincode.Text + "','" + ddldistrict1.SelectedItem.Text + "','" + st + "','" + txtcontact.Text + "','"+ txtschooladdress.Text +"','"+ txtschoolpincode.Text +"','"+ ddldistrict2.SelectedItem.Text +"')";
cmd = new OleDbCommand(qql, con);
int res;
res = cmd.ExecuteNonQuery();
res = 1;
con.Close();