hi I'm having some trouble running this sql and I get an error #3464 Data type mismatch in criteria expression.

What I'm trying to do is update [tbl_Account]![Available] a Yes/No field to Yes in my after I assign it.
Code:
Dim strSQLb As Variant
strSQLb = DLookup("[ACCOUNT]", "qry_Avail_ACCOUNTS")
DoCmd.RunSQL "Update tbl_ACCOUNTS SET tbl_ACCOUNTS.Used= Yes  where tbl_ACCOUNTS.ACCOUNT=" &
...