stored procedure problem

I am trying to write a stored procedure that I can execute with a given client name, and pass that client name as param to the create table statement inside the stored procedure.  Here is the syntax I have:

IF EXISTS (SELECT name
         FROM   sysobjects
         WHERE  name = 'Build_Invoice'
         AND         type = 'P')
    DROP PROCEDURE Build_Invoice
GO

CREATE PROCEDURE Build_Invoice (@Client Varchar(30) = " ")
AS
Set @Client=@Client + '_Invoice'

CREATE TABLE dbo.@Client (
      [Column1] [char] (1) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL ,
                [Column2] [char] (10) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL
) ON [PRIMARY]
GO


I am testing in by running this:

execute Build_Invoice 'Test' and expecting to get Test_Invoice as table name.  I can create the sp just fine, but I cannot pass the param.  Help!!!

Thanks in advance,

IPT