Login Bug

				if(Svasta == 0)
				{
                    Svasta++;
                    new stringb;
				    format(stringb, sizeof(stringb), ""COL_AGRP"Dobrodosli nazad "COL_BIJELA"%s, "COL_AGRP"na "COL_BIJELA"Arena Gaming RolePlay "COL_AGRP"server.\nU prazni prostor ispod unesite vasu lozinku:\nImate jos "COL_BIJELA"3 "COL_AGRP"pokusaja", GetName(playerid));
					SPD(playerid, DIALOG_LOGIN, DIALOG_STYLE_PASSWORD, ""COL_BIJELA"Login", stringb, "Login", "Kick");
				}
				else if(Svasta == 1)
				{
                    Svasta++;
                    new stringb;
				    format(stringb, sizeof(stringb), ""COL_AGRP"Dobrodosli nazad "COL_BIJELA"%s, "COL_AGRP"na "COL_BIJELA"Arena Gaming RolePlay "COL_AGRP"server.\nU prazni prostor ispod unesite vasu lozinku:\nImate jos "COL_BIJELA"2 "COL_AGRP"pokusaja", GetName(playerid));
					SPD(playerid, DIALOG_LOGIN, DIALOG_STYLE_PASSWORD, ""COL_BIJELA"Login", stringb, "Login", "Kick");
				}
				else if(Svasta == 2)
				{
                    Svasta++;
                    new stringb;
				    format(stringb, sizeof(stringb), ""COL_AGRP"Dobrodosli nazad "COL_BIJELA"%s, "COL_AGRP"na "COL_BIJELA"Arena Gaming RolePlay "COL_AGRP"server.\nU prazni prostor ispod unesite vasu lozinku:\nImate jos "COL_BIJELA"1 "COL_AGRP"pokusaj", GetName(playerid));
					SPD(playerid, DIALOG_LOGIN, DIALOG_STYLE_PASSWORD, ""COL_BIJELA"Login", stringb, "Login", "Kick");
				}
				else if(Svasta == 3)
				{
                    Svasta = 0;
					apac_Kick(playerid, "AngelAC: Pogrijesili ste 3 puta lozinku. Kick.");
				}
			}
		}
	}

stock apac_Kick(playerid, razlog[])
{
	SetTimerEx("KickTimer", 300, false, "d", playerid);
	SendClientMessage(playerid, COLOR_APRP, razlog);
	return 1;
}

if(dialogid == DIALOG_LOGIN)
	{
	    if(!response) return apac_Kick(playerid, "AngelAC: "COL_BIJELA"Prekinuli ste login. Kick.");
		if(response)
		{
		    if(!strcmp(inputtext, PlayerInfo, false))

stock apac_Kick(playerid, razlog[])
{
	SetTimerEx("KickTimer", 300, false, "d", playerid);
	SendClientMessage(playerid, COLOR_APRP, razlog);
	return 1;
}

forward KickTimer(playerid);
public KickTimer(playerid)
{
	if(fexist(UserPath(playerid)))
	{
		SacuvajIgraca(playerid);
		Kick(playerid);
	}
	else if(!fexist(UserPath(playerid)))
	{
		Kick(playerid);
	}
	return 1;
}

This function returns 0 if either string is empty. Check for null strings with isnull(). If you do not, for example, people can login to anyone's account by simply entering a blank password.

// Check for null strings with isnull()
if(!strcmp(string1, string2) && !isnull(string1) && !isnull(string2))
 
// Definition for isnull():
#if !defined isnull
    #define isnull(%1) ((!(%1)) || (((%1) == '\1') && (!(%1))))
#endif