getting error in insert query while inserting valuethrough textbox..
//code
string firstname = txt_first_name.Text.Trim();
string middlename = txt_middle_name.Text.Trim();
string lastname = txt_last_name.Text.Trim();
string address = txt_address.Text.Trim();
string Mobile_No = txt_mob_no.Text.Trim();
string birthdate = Convert.ToString(txt_birthdate.Text.Trim());
string gender = Rdo_gender.SelectedIndex.Trim();
string email_id = txt_email.Text.Trim();
string user_name = txt_userid.Text.Trim();
string password = txt_pass.Text.Trim();
string confirm_password = txt_confirm_pass.Text.Trim();
string country = txt_country.Text.Trim();
string city = txt_city.Text.Trim();
string querystr= "insert into DSProfile.HDR_PROFILE(first_name, middle_name,last_name , address , contact_number, birth_date, gender, email_id, user_name , password , confirm_password ,country , city)" + " values
('" + firstname + "','" + middlename + "', '"+lastname+"','"+ address +"','"+ Mobile_No+"','"+birthdate+"','"+gender+"','"+ email_id+"','"+user_name+"', '"+password+"','"+ confirm_password+"', '"+ country+"','"+ city+"')";