[Kirollos]

if(!strcmp(inputtext,PlayerInfo[playerid][Password]))return ShowPlayerDialog(playerid, DIALOG_LOGIN, DIALOG_STYLE_INPUT,""COL_WHITE"Login",""COL_RED"Yo u have entered an incorrect password.\n"COL_WHITE"Type your password below to login.","Login","Quit");

translating this to human language:

if the inputtext equals to the password, it shows him the dialog saying password incorrect.