H1b換學校，H4需要材料嗎? Form I-539

第一次換學校，也是從H1b=>H1b, 沒有給H4辦什麽材料。
這次也是H1b=>H1b，學校到學校，這第三個學校要求填
Form I539.
http://uscis.gov/graphics/formsfee/forms/i-539.htm
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Purpose of Form: This form is used by some nonimmigrants to request extensions of stay or changes from one nonimmigrant category to another nonimmigrant category. Please see the form's instructions for your specific nonimmigrant visa category.

It is used by F and M nonimmigrants seeking reinstatement of status.

It is also used by K-3/4 nonimmigrants to request extensions of stay and by persons seeking V nonimmigrant status while in the United States or extension of stay as a V nonimmigrant.
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上麵雖然沒有提到H4,但是在表格的填寫指南中有專門的H4一欄．

有誰填過這個539表，能不能分享一下經驗？
有知道的也請回答，先謝過了。