很不幸，您可能無法對您的房東提出訴訟

根據紐約市Tenant Rights 的基本概念
http://tenant.net/faq.txt
如果您承認這是一個 SUBLETTING OR ASSIGNING LEASES
根據以下的概念您的房東有權要求您付出半個月的房租 (原文如下)
The prime tenant, not the subtenant, retains the rights to arenewal lease and any rights resulting from a co-op conversion. The term of a sublease may extend beyond theterm of the prime tenant's lease. (Real Property Law Sec. 226-b, RSL Sec. YY51-6.0(12))

如果您以對方沒有給您written 蒩約，否認這是一個 SUBLETTING OR ASSIGNING LEASES 的行為, 則您隻是 SHARING APARTMENTS 則根據下麵的概念
The tenant is the person or persons who signed the lease, and the occupant is the person who moves in after the lease is signed. The tenant retains the rights under the lease and is the only person who may renew a lease once it expires.
則對方也有權要求您負擔部份的房租，所以老實說對方的行為也算合法。(同時對方也表示，如果找到新的住客會退還您的租金，所以並不算是侵占，所以在小額法庭，您也沒有case)
如果您要更多的資料請到下麵的網站查詢
http://www.megalaw.com/ny/top/nylandlord.php

對了，還有一件事，您於您房東的爭議在紐約市應該屬於houng court管轄，相關網站如下http://tenant.net/Court/barguide/court.html
所以 Judge Judy 的管轄權可能管不到這個案件。