[JustBored]

Try declaring the variable forsaleznak as a player variable

pawn Код:

new forsaleznak[MAX_PLAYERS];
//then in the command
if(strcmp(cmd, "/srediznakce", true) == 0)
    {
        if(xkukja2[playerid] != 0)
        {
            new Float:x,Float:y,Float:z;
            GetPlayerPos(playerid,x,y,z);
            forsaleznak[playerid] = CreateObject(19471, x, y, z+2, 0.0, 0.0, 0.0);
            EditObject(playerid, forsaleznak);
        }
        else
        {
            SendClientMessage(playerid, WHITE, "{F20000}GRESKA: {FFFFFF}Koristete prvo /kreirajkukja !");
        }
    }
//do the same with onplayereditobject