Interesting tutorial. Thanks to Lauriana - http://petitmainsauvage.blogspot.nl/2010/10/promised-tutorial.html
Instead of knit fabric, I tried out pattern on chiffon and also lengthened my blouse; It turned out great!!!
I however realized that, the height of the back collar (7 cm) after completing blouse was quite high (could be because I used chiffon), so I folded it over and it was just fine.