Actually i was hosting my site as add on domain of my hosting account under my main site under public_html folder
Addon wordpress domain site was hosted in folder public_html/www.xyz.com/
xyz is the main i created sub domain for that
Now i taken spearate hosting for http://www.xyz.com uploaded in same way public_html/www.rojlo.com (also uploaded database)
yes created sub domain in this new hosting account for each website (Example:- ask.xyz.com)
Now i am getting error "Error establishing a database connection"
(what changes i need to do in database to running like a simple http://www.xyz.com having subdomains like ask.xyz.com)