is it a good idea to put this on contract?

[Account Closed]

this lady says

"was wondering if it was possible for you to put into the contract that you will be paying off the back taxes on the house and the levy"

how do i add this into the contract?

[Michael Quarles]

I would state the following... 

Buyer is buying property Subject to the Existing Mortgage(s)/Loan(s) and/or Lien(s) encumbering the property in the amounts not to exceed: $______________. 00.

If the existing balances at the time of closing are less than the amounts stated above, purchase price will be reduced by the difference. If balances are higher then shown, then Seller’s proceeds will be reduced accordingly.