Find a string in HTML and print value : I'm posting to a webpage and in my respose I get a big chunk of HTML that will change next request. 
With groovy I'd like to find this string:

var WPQ1FormCtx = {"ListData":{"owshiddenversion":23,

The value "23" will change next time I post to the webpage, and I need that value.

With .contains I'll find if string exists.

    def htmlParse = Jsoup.parse(htmlResponse)
    log.info a.contains('var WPQ1FormCtx = {"ListData":{"owshiddenversion":23,') 

But I need to write out the value after 'var WPQ1FormCtx = {"ListData":{"owshiddenversion":**xxxxx**, 
that can be anything from 1 to 100 000.