"too many arguments" message

[jmvidalvia]

Hi everybody!
My first post here...hope to learn quickly.
I just mounted a debian server and start to run some few scripts. They "seem" to run, but sometimes (5% of times) I am getting this error message:

/home/jmd/sh/cartas.sh: line 2: [: too many arguments

This is /home/jmd/sh/cartas.sh:

#!/bin/bash
if [ -z $(ls /home/as400/cartas) ]
then
        echo "" > /dev/null
else
        /home/jmd/sh/cartastxt.sh
fi

And this is /home/jmd/sh/cartastxt.sh

#!/bin/bash
touch /home/as400/cartas/prueba.txt
chown nobody:desa /home/as400/cartas/*
chmod 660 /home/as400/cartas/*
mv /home/as400/cartas/* /home/datos/comercial/cartas/
rm /home/datos/comercial/cartas/prueba.txt

What is driving me crazy is that messages just appear sometimes.
Youy might know that files are send to /home/as400/cartas from a IBM iseries using ftp.
Thank you very much for your help!

[Motoma]

You are getting an the error "Too many arguments" on this line:

if [ -z $(ls /home/as400/cartas) ]

What are you trying to do here? What could the message be referring to as arguments?