not able to select the database

hi ,
iam a newbie. need help.. i wanted to host wordpress locally. iam using wamp. iam getting the following error:

[ Can’t select database
We were able to connect to the database server (which means your username and password is okay) but not able to select the database_name_here database.

Are you sure it exists?
Does the user root have permission to use the database_name_here database?
On some systems the name of your database is prefixed with your username, so it would be like username_database_name_here. Could that be the problem? ]

please help what do i need to do with the database name do i needto change it? if yes then what do i name it as ?
please help

thank you in advance

regards