无法使用“复制数据库”向导在同一服务器中复制数据库

I have sql server 2008 R2. and I want to take a copy of a database inside the same database server. so I will have exact copies of the database. now I login to the sql server management studio>> right click on the database >> tasks>>copy database. where I was prompted with the copy database wizard. I select the database I want to copy, and I name the new copy as I have sql server 2008 R2. and I want to take a