instructions

1I-797
2. You will require a comprehensive letter from your employer identifying you and describing in detail the nature and duties of your position, the company you work for and its business standing and markets to justify the need for the visa extension. The letter submitted must be on your employers letterhead. The letter must have an 'original' signature from the company representative and must be addressed to the Visa Office, Department of State. Do NOT sign the leter yourself, as the Visa Office will NOT accept letters signed by the visa applicant.
3.A typed nonimmigrant visa application form, OF-156, with one 'official' passport-size photograph for each applicant, regardless of age. The photographs must be attached to the respective forms in the designated place. You should spell out the month of birth (i.e., write "March 27th," NOT 1/2 or 2/1). Incomplete or improperly filled out applications will be returned without visas.