[TomHarper]

In this particular line of code

Code:

format(l_sQuery, sizeof(l_sQuery), "SELECT * FROM `USUARIOS` WHERE Nick = '%q' COLLATE NOCASE AND Password = '%q'", GetPlayerNameEx(playerid), PI[playerid][e_sPassword]);

You seem to be using an already loaded password here. You need to get the password value from the "inputtext" variable which contains the value of the responded dialog. Which would go like this.

Code:

format(l_sQuery, sizeof(l_sQuery), "SELECT * FROM `USUARIOS` WHERE Nick = '%q' COLLATE NOCASE AND Password = '%q'", GetPlayerNameEx(playerid), inputtext);