how to purchase bigrock domain and ad to blogger

first choose good  domain in bigrock.com 
on big rock website 

frist choose get a domain tab  mouse cursor press next click on
domain name registration 
then search what domain you want
next check out and then create new account

After sign in the bigrock account
and then purchase your domain by credit or debit card or any options
in this bigrock account click on your purchase  domain link
and then right side bar some option are there
1 web hosting
2 multi domain hosting
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- dns management
then click on ->dns mangement
then click on -> manage dns
and then open new window
some tab option are there click on -> A record
and then click on -> add a record
1. some option are there
host name                          -  leave it blank
Destination IPv4 Address  -  216.239.32.21
TTL                                  - Leave as defalt
                                         Click on -> add record
                                           
again click on -> Add a record
2. some option are there
host name                          -  leave it blank
Destination IPv4 Address  -  216.239.34.21
TTL                                  - Leave as defalt
                                         Click on -> add record
3. some option are there
host name                          -  leave it blank
Destination IPv4 Address  -  216.239.36.21
TTL                                  - Leave as defalt
                                         Click on -> add record
again click on -> Add a record
4. some option are there
host name                          -  leave it blank
Destination IPv4 Address  -  216.239.38.21
TTL                                  - Leave as defalt
                                         Click on -> add record

these complete then click on -> cname records
and then click on -> Add cname record
host name                        - www

value                               - ghs.google.com 
TTl                                  - Leave as defalt
                                       Click on -> add record









then  sign into blogger account     
click on your site dashboard
then click on settings - basic -
then publishing opthion
Then clink on -> add a custom domain 
and then click on ->  Switch to advanced settings
and the type-> www.sample.com                   like this domain format
and save it show an error 12
give some 2 codes for verification
1 code paste - cname records- host name
2 code paste - cname records - value
Click on -> add record
go to blogger repeat 
then  sign into blogger account     
click on your site dashboard
then click on settings - basic -
then publishing opthion
Then clink on -> add a custom domain 
and then click on ->  Switch to advanced settings
and the type-> www.sample.com
Save it and enjoy your blogspot site is redirect to domain name
Thank u