Dear Mr. Asifbd_2012,
An employee under the terms of employment with company's "At-will" is an employee referred to as not under the contract with the company. An At-will employee can be at any time "fired out" for almost any flippant reason thereof; not although employee do also have the similiar right to quit the job at any time without further notice to the employer.
How do you know "AT-WILL" is a best term to be fit into the appointment letter without knowing the basic rights of such employee? --
Lay -off for at-will employees - Though the employer has unmitigated rights to sack/fire the employee; the lay-off falls under the minimum requisition of notice period to the employee only in case of
(i) no bias towards race, caste, creed, sex, marital status, religion & country specific reasons.
Employee right to At-will termination - Here the employee termination policy has to be differed which states, Firing should be done only in case of Performance or behavioural aspects and not to call a halt due to unecessary cause.
Most importantly, employers have new employees sign a form stating that they are being hired on an at will basis. It should also be made a point that not only the employee signs this form but should also be signed by the employer which implies verbal and writing protecting against the legal remedy to help protect loss of time.
Hope the above will definitely help you enquire before you suggest anything on at-will employment.