Any agreement or offer letter you sign with your employer or vendor should not obligate you to work for them beyond a two week notice or a months notice in some cases. Read every line and in between them and make sure you understand every point. Talk to a lawyer if you are not sure and if your employer does not give you enough clarification. Try to add a clause which explicitly states your two week notice.
Bare the application fees if you have to and do not sign any agreements that bond your to slavery.If you have already signed such agreement talk to a lawyer and see what it takes to break the bond. In most cases these agreements do not stand in court and your employer does not want the hassle of getting black listed either. What looks like a great opportunity to sign any kind of agreement today might soon be obsolete as the markets improve and you find better opportunities. Never sign an offer letter or contractual agreement that obligates your duration of employment in exchange for your green card or visa fee/sponsorship.
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