Using Custom Fields

Hi,

I have a question about custom fields.

I have a custom field as below :

Key = Theme Home Page:

Value = http://www.example.com/

Now, I want to show this key on ” single post ” page, if only it has value.

like :

Theme Home Page: http://www.example.com/

If any theme has not home page, nothing will be displayed.

How can I ?

And I also want to add link at value.

How can I ?

Thanks.

asony