[Kane]

Just show a dialog with the 'rules' and if there's a response, check if it's a registered account / registered like you would. For example:

PHP код:

#define DIALOG_SERVER_RULES (1)
public OnPlayerConnect(playerid)
{
    new 
        rule_str[128]
    ;
    
    strcat(rule_str, "Don't cheat obviously...\n"); 
    strcat(rule_str, "Don't break rules...\n");
    
    ShowPlayerDialog(playerid, DIALOG_SERVER_RULES, DIALOG_STYLE_MSGBOX, "Rule confirmation", rule_str, "Confirm", "Cancel"); 
}
public OnDialogResponse(playerid, dialogid, response, listitem, inputtext[])
{
    switch(dialogid)
    {
        case DIALOG_SERVER_RULES:
        {
            if(response)
            {
                //This is where your code to check if their account exists would go.
                return 1;
            }
            else Kick(playerid);
        }
    }
    return 0;
} 


And different "backgrounds" are just textdraw sprites.

https://sampwiki.blast.hk/wiki/TextDraw_Sprites