SQL Server: Find out default value of a column with a query

How can I find out the default value of a column in a table using a SQL query?

By using this stored procedure:

sp_columns @tablename 

I get some information on the columns of a particular table but the default value of the columns is missing, How can I get it?

You can find the stored definition with the below (remember to adjust the column and table name to find to be ones relevant to your environment!)

SELECT object_definition(default_object_id) AS definition
FROM   sys.columns
WHERE  name      ='colname'
AND    object_id = object_id('dbo.tablename')

I use INFORMATION_SCHEMA table like this:

SELECT 
    TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME, COLUMN_DEFAULT
FROM
    INFORMATION_SCHEMA.COLUMNS
WHERE
  TABLE_SCHEMA = @SchemaName 
  AND TABLE_NAME = @TableName
  AND COLUMN_NAME = @ColumnName;