sqlconnection conn=new sqlconnection();
sqlcommand cmd=new sqlcommand();
string query="insert into tablename(column1,column2) values(''column1 value'',''column2 value'') ";
cmd.connection=conn;
cmd.commandtext=query;
conn.open();
cmd.executenonquery();
conn.close;

string s = "INSERT into UserDetails values(''" + txtemail.Text + "'',''" + txtfirstname.Text + "'',''" + txtlastname.Text + "'',''" + txtpwd.Text + "'',''" + ddlcountry.SelectedItem.Text + "'',''" + ddlstate.SelectedItem.Text + " '',''" + txtcity.Text + "'',''" + txtphnumber.Text + "'',''" + txtaddress1.Text + "'',''" + txtaddress2.Text + "'',''" + txtqualification.Text + "'',''" + txtskills.Text + "'')";
            SqlCommand cmd;
            cn = new SqlConnection(conection.getconnection());
            cmd = new SqlCommand(s, cn);
            cn.Open();
            cmd.ExecuteNonQuery();
            cn.Close();