title: regex for allowing SINGLE white space in between words
body: <p>I m using the following regex for the same:
  ^\S.*\S$</p>
  
  <p>but this regex is not working in case of multiple spaces in between words.
  and one more thing, it doesnt allow you to enter a single character</p>
  
  <p>I want to validate no leading and trailing space and single white space in between words, words can include anything alphanumeric as well as special character.</p>
  
  <p>if i m trying to enter 'a' in the text box, its not accepting</p>