How to check if a 'Storage ' entry exists?

OK, thanks, but all of my files have a .txt extension, and those are not recognised by your code :(

s = require('Storage');

print(s.list());

filename = 'news.txt';
if (s.read(filename)!==undefined) {
  print("exists");
} else {
  print("does not exists");
}

Output is:

[
"news.txt\1",
"weath0.txt\1",
"weath1.txt\1",
"stocks.txt\1",
"messages.txt\1"
]
does not exists