[EiresJason]

You should always try debugging the code.

EDIT: Just noticed - you're declaring message as a integer aswell.

pawn Код:

new id, str1[128], str2[128], message[128], adminmsg[128];

pawn Код:

CMD:msg(playerid, params[])
{
    new id, str1[128], str2[128], message, adminmsg[128];
    if(pInfo[playerid][pAdmin] < 1) return 0;
    print("reached 1");
    if(sscanf(params,"us[128]",id,message)) return SCM(playerid, COLOR_WHITE,"Syntax: /msg [playerid/partofname] [message]");
    print("reached 2");
    format(str1, sizeof(str1), "%s", params); //change from params to message so it doesnt take in the ID you entered.
    print("reached 3");
    format(str2, sizeof(str2), "{FF0000}Message From Admin:{FFFFFF}%s(%d)", PlayerName(playerid), playerid);
    print("reached 4");
    ShowPlayerDialog(playerid, anotice, DIALOG_STYLE_MSGBOX, str2,str1,"Close",""); //I think you should be sending this to id btw :P
    print("reached 5");
    format(adminmsg, sizeof(adminmsg), "{1B8AE4}%s(%d){FFFFFF} messaged {1B8AE4}%s(%d){FFFFFF}: %s", PlayerName(playerid), playerid, PlayerName(id), id, message);
    print("reached 6");
    SendMessageToAdmins(-1, adminmsg);
    return 1;
}

CMD:admin(playerid, params[])
{
    new message, adminmsg[128];
    if(sscanf(params,"s[128]",message)) return SCM(playerid, COLOR_WHITE,"Syntax: /admin [message]");
    print("reached A");
    format(adminmsg, sizeof(adminmsg), "Message From: {1B8AE4}%s(%d){FFFFFF}: %s", PlayerName(playerid), playerid, message);
    print("reached B");
    SendMessageToAdmins(-1, adminmsg);
    print("reached C");
    SCM(playerid, -1, "Your message has been sent to all online admins.");
    return 1;
}

EDIT2:
You could make this work with just 2strings.

pawn Код:

CMD:msg(playerid, params[])
{
    new id, str[128],message[128];
    if(pInfo[playerid][pAdmin] < 1) return 0;
    if(sscanf(params,"us[128]",id,message)) return SCM(playerid, COLOR_WHITE,"Syntax: /msg [playerid/partofname] [message]");
    format(str, sizeof(str), "{FF0000}Message From Admin:{FFFFFF}%s(%d)", PlayerName(playerid), playerid);
    ShowPlayerDialog(id, anotice, DIALOG_STYLE_MSGBOX, str,message,"Close","");
    format(str, sizeof(str), "{1B8AE4}%s(%d){FFFFFF} messaged {1B8AE4}%s(%d){FFFFFF}: %s", PlayerName(playerid), playerid, PlayerName(id), id, message);
    //SendMessageToAdmins(-1, str);
    return 1;
}

CMD:admin(playerid, params[])
{
    new message[128], adminmsg[128];
    if(sscanf(params,"s[128]",message)) return SCM(playerid, COLOR_WHITE,"Syntax: /admin [message]");
    print("reached A");
    format(adminmsg, sizeof(adminmsg), "Message From: {1B8AE4}%s(%d){FFFFFF}: %s", PlayerName(playerid), playerid, message);
    print("reached B");
    SendMessageToAdmins(-1, adminmsg);
    print("reached C");
    SCM(playerid, -1, "Your message has been sent to all online admins.");
    return 1;
}