Thanks Master pjiang and 863211 answer my questions regarding h4pending->h1.
h4 may take couple months approved. If I have a job offer now, I have to wait h4 approved, then change status from h4->h1.
我有一个这样的想法，不知可行不？
请原公司写一份信，写明我的工作将于８月３０日结束，从６／３０－８／３０，I take unpaid leave to take care my family. 是不是有了这样的一封信， 我就可以withdraw h4, then I am still considered as h1, I just need do h1 transfer to new company. I can start work for new company once I got notice receipt. Is it correct?