I am creating CLUSTERED INDEX by running below query on sql server 2005

CREATE TABLE dbo.Example

(

col1 varchar(Max) NULL,

);

GO

CREATE VIEW dbo.ExampleUnique

WITH SCHEMABINDING AS

SELECT e.col1

FROM dbo.Example AS e

WHERE e.col1 IS NOT NULL;

GO

CREATE UNIQUE CLUSTERED INDEX cuq

ON dbo.ExampleUnique (col1);

GO

It shows error: Column 'col1' in table 'dbo.ExampleUnique' is of a type that is invalid for use as a key column in an index.

Any suggestions