screen-ir: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/screen-ir - from package: iselect

You may install the required package with command apt-get install {package}

Error in other languages:
screen-ir: bevel nie gevind nie
screen-ir: comandă negăsită
screen-ir: comando não encontrado
screen-ir: commande introuvable
screen-ir: command not found
screen-ir: käsku ei ole
screen-ir: không tìm thấy lệnh
screen-ir: komanda nerasta
screen-ir: Kommando nicht gefunden.
screen-ir: kommandot finns inte
screen-ir: komut yok
screen-ir: nie znaleziono polecenia
screen-ir: níor aimsíodh an t-ordú
screen-ir: no se encontró la orden
screen-ir: no s'ha trobat l'ordre
screen-ir: opdracht niet gevonden
screen-ir: parancs nem található
screen-ir: perintah tidak ditemukan
screen-ir: príkaz nenájdený
screen-ir: příkaz nenalezen
screen-ir: команда не найдена
screen-ir: командата не е открита
screen-ir: 命令找不到
screen-ir: コマンドが見つかりません