Regex validator question

[Stephan Bour]

I¹m trying to validate a field that can have up to 150 word characters but
any number of white space, carriage returns or tabs.
This doesn¹t work properly:
ValidationExpression="^[\w]{1,150}[\n\s]{0,}"

I get a validation error if any non-word character is added, regardless of
the total length of the string.
Thanks for your help,
Stephan.