>>Try building your error message into a varchar variable first, and then just use the @variable for the message parameter. I think trying to build the message in the parameter is a problem.
>
>Then only I could have it working is by this approach.
>
>Message #1504520

The simplest way to answer this question is to check BOL for Raiserror. It clearly states how to use parameters (C++ style) in the string.