It is not OK unless your original charger and the new one are both USB type. To tell is easy; the part that plugs into the wall will have a normal computer-type USB connector on it, which the phone cable connects to.
If you use the wrong charger, you don't just risk having the battery not charge fully. You also have the risk that it won't charge at all, or the risk that you will damage the battery or the phone - even (maybe) cause a fire or explosion.
It is not OK unless your original charger and the new one are both USB type. To tell is easy; the part that plugs into the wall will have a normal computer-type USB connector on it, which the phone cable connects to.
If you use the wrong charger, you don't just risk having the battery not charge fully. You also have the risk that it won't charge at all, or the risk that you will damage the battery or the phone - even (maybe) cause a fire or explosion.