TE_get_text_line don't work

Hi!

I'm trying to get a value via TE_get_text_line but it doesn't work. 

TE_type("clear<kReturn>");

TE_type("echo $(($(date +%s%N)/1000000))>zeit.txt<kReturn>");

TE_get_text_line(1, 2, -1, zeita0001);

and if I put "lr_output_message ("zeita0001=%s", zeita0001); " in the script, it shows "zeita0001=(null)"

What is the problem here?