The EXECUTE permission was denied on the object ‘xxxxxxx’, database ‘zzzzzzz’, schema ‘dbo’

I’m having problems executing a function.

Here’s what I did:

1. Create a function using SQL Server Management Studio. It was successfully created.
2. I then tried executing the newly created function and here’s what I get:

The EXECUTE permission was denied on
the object ‘xxxxxxx’, database
‘zzzzzzz’, schema ‘dbo’.