It's better to use INFORMATION_SCHEMA views than query system tables directly

SELECT * FROM
	pubs.INFORMATION_SCHEMA.COLUMNS
WHERE table_name = 'authors'	

>
>I have the following query:
>
>select c.name,t.name,c.length, cc.text as [default]
>from systypes t,sysobjects o, syscolumns c ,syscomments cc
>where 1=1
>and c.id=o.id
>and t.xtype=c.xtype
>and c.cdefault*=cc.id
>and o.name='tblcustomers'
>and t.name<>'sysname'
>order by c.colorder
>
>It gives me column name, type, size, default value - how do I find out if the field allows nulls?
>