Prepare journal entries for each of the following transactions:
1. Issue common stock for $21,000.
2. Obtain $9,000 loan from the bank by signing a note.
3. Purchase construction equipment for $25,000 cash.
4. Purchase advertising for the current month for $1,100 cash.
5. Provide construction services for $18,000 on account.
6. Receive $13,000 cash on account from previous services to customers.
7. Pay salaries for the current month of $6,000.