question about melee

i was wondering if there is anybutton to switch through targets on the melee system or to de target some one quickly if there is please tell me and how to do it thanks in advance

No there is not, you can only change by clicking directly on a new target.

The way I do it is, I can change weapons with my scroll wheel on my mouse. So I just change to a different weapon and then change back right away and then I can click on a new target.

But going straight from one target to another, I don't think there is a button to do that

that is indeed the best way