How to apply for transfer after the first semester?

Hi ,

I joined in an university for 2013 fall (MS in CS). I wish to transfer to a different university from the second semester. I DONOT have an admit from the university i intend to transfer.
Please let me know how to apply for transfer to another university.
And also when to apply?

First, you need to get admission. You just need to apply to the school you intend to transfer for the semester you wish to transfer. When you apply, you mention that you are in US and intend to transfer. Easy way is to go to school and meet them or call them and sort it out. There are articles on blog for transfer process, search for it.