title: sed + remove spaces between different char with "," seperator between them
body: <p>param can be one
   of the following</p>
  
  <p>a,b   ,   f,     d     </p>
  
  <p>or</p>
  
  <p>a, b     , c,    e       </p>
  
  <p>or</p>
  
  <p>r , q  ,c , d</p>
  
  <p>but we want a,b,c,d without spaces</p>
  
  <p>for example if we get: a , b ,c,d
  need to change it to a,b,c,d
  sytax to do that
  yael</p>
  
  <p>what the best sed syntax to change it</p>