transfer value from textbox and a table1 to another table2

I am trying to enter some data into a table2 from textboxes and some data from A sql databse table1 but all logics gone fail. please help here is the code for your reference.

string qry = "insert into sale (inno,date,type,custname,item,qty,price,dis,disa,gst,gsta,total) values (" + invoice + ",'" + dt + "','" + paytype + "','" + custname + "','" + item + "'," + iqty + "," + iprice + "," + idisc + "," + idsa + "," + igst + "," + igsta + "," + itot + ") and insert into sale (hsn,sgst,cgst) select hsn,sgst,cgst from stock";
// string qry1 = "";
// SqlCommand sc1 = new SqlCommand(qry1, con);
SqlCommand sc = new SqlCommand(qry, con);
// int j = sc1.ExecuteNonQuery();
int i = sc.ExecuteNonQuery();
if (i >= 1)
MessageBox.Show("Inserted Succesfully");
else
MessageBox.Show("Not Done");