i am trying to backup a database but couldn't find any solution to it the last tecnique i used was that i made a procedure in which i write

BACKUP DATABASE database name
TO DISK ='E:/database.bak'

But i got the following Exception/Error

"Could not locate entry in sysdatabases for database 'DB_1'. No entry found with that name. Make sure that the name is entered correctly.
BACKUP DATABASE is terminating abnormally."