[TonyII]

pawn Код:

new bool:doingAnim[MAX_PLAYERS char];

//Under your animation cmd
doingAnim{playerid} = true;

public OnPlayerKeyStateChange(playerid, newkeys, oldkeys)
{
    if (newkeys & KEY_FIRE)
    {
    if (doingAnim{playerid})
    {
        ClearAnimations(playerid);
        doingAnim{playerid} = false;
    }
    }
return 1;
}

EDIT:
If you want it to be RMB, just simply replace KEY_FIRE with KEY_AIM