public PlayerToPlayer

forward PlayerToPlayer(Float:radi, playerid, targetid);
public PlayerToPlayer(Float:radi, playerid, targetid)
{
    if(IsPlayerConnected(playerid) && IsPlayerConnected(targetid) && GetPlayerVirtualWorld(playerid) == GetPlayerVirtualWorld(targetid))
    {
        new Float:posx, Float:posy, Float:posz;
        new Float:oldposx, Float:oldposy, Float:oldposz;
        new Float:tempposx, Float:tempposy, Float:tempposz;
        GetPlayerPos(playerid, oldposx, oldposy, oldposz);

        GetPlayerPos(targetid, posx, posy, posz);
        tempposx = (oldposx -posx);
        tempposy = (oldposy -posy);
        tempposz = (oldposz -posz);

        if (((tempposx < radi) && (tempposx > -radi)) && ((tempposy < radi) && (tempposy > -radi)) && ((tempposz < radi) && (tempposz > -radi)))
        {
            return 1;
        }
    }
    return 0;
}