OpenEuphoria

What is wrong with this code?

include std/pretty.e 
include std/sequence.e 
include std/io.e 
atom fn = open( "eingabe.csv", "r" ) 
object data = read_lines( fn ) 
close(fn) 
sequence mist = split(",",data[1]) 
puts(1,data[1]) 
puts(1,"\n") 
pretty_print(1,mist[2]) 
-- this line gives an error because data[1] wasn't splitted as expected 
-- mist[1] still contains the whole inputstring of line no. 1 
puts(1,"\n") 

I've tried different solutions with the split function in regex.e and an appropriate regular expression but that doesn't work either. In this case, the sequence mist contains another sequence that contains all the single bytes of data[1]. I experimented already a few hours with no useful results. Maybe I have overseen something.

Thanks in advance for helping me!