I have a metro pcs Micro sim can i use it on iphone 4 att?

I went to metro pcs store and i saw that the new phones that are coming out use a micro sim that iphone uses now so my question is that i have an iphone 4 att is not unlocked or jaillbreaked i want to know if i could use it for Metro?

Sadly no You would have to first unlock the phone to do this

You are not able to use it. For this you must unlocked it first.