select statement returns null in stored proc

If I run this statement in Query Analyzer, it properly returns 1
for my testing table.  But if I put the statement into a stored
procedure, the stored procedure returns NULL.  What am I doing
wrong?  I suspect it may be related to how I defined the parameters
for the stored procedure. Perhaps my definition of TableName and
ColumnName don't match what COLUMNPROPERTY and OBJECT_ID expect to
receive, but I don't know where to look for the function declarations
for those.  Any pointers would be appreciated.

Select statement:
SELECT  COLUMNPROPERTY(OBJEC
T_ID('Table1'), 'TestID', 'IsIdentity') AS
IsIdentity

Table definition:
CREATE TABLE [dbo].[Table1] (
[TestID] [numeric](18, 0) IDENTITY (1, 1) NOT NULL ,
[Description] [varchar] (50) COLLATE  SQL_Latin1_General_C
P1_CI_AS NO
T NULL
) ON [PRIMARY]

Stored Procedure definition:
CREATE PROCEDURE spTest
(@TableName varchar,
@ColumnName varchar)
AS SELECT      COLUMNPROPERTY(OBJEC
T_ID(@TableName), @ColumnName,
'IsIdentity') AS IsIdentity

You need to specify lengths for your varchar parameters

CREATE PROCEDURE spTest
(@TableName varchar(50),
@ColumnName varchar(50))

markc600@hotmail.com  wrote:
> You need to specify lengths for your varchar parameters
>
> CREATE PROCEDURE spTest
> (@TableName varchar(50),
> @ColumnName varchar(50))

That was it.  Thanks.