how to get the month first & last dates by month name in sql

Question

Hi

 

I have a web form in that I have two dropdown values where I can select year, basing on year I can select particular month. Now I am sending this month name as parameter to database, in db basing on month name I have get the first date and last date of month which was passed as parameter to sql server 2012

 

I have stuck at this point to retrieve them 

 

Any help Thanks in Advance