>>>>What is the type of the field? Is it CHAR or varchar? As Boris showed, it doesn't work with char field.
>>>
>>>It is nvarchar
>>
>>Ok, what is your command which you printed and have you tried executing it?
>
>this is what gets printed:
>
>

SELECT [dbo].[Receipts].[PolicyHeaderFK],
>		[ReceiptAmount],
>		[ReceiptDate],
>		[ReceiptNumber],
>		[ReceiptPK],
>	    [ClientFK],
>		[PlanFK],
>		[PolicyNumber],
>		[PolicyPK],
>		[Code],
>		[Description],
>		[ClientNumber],
>		[CompanyName],
>		[FirstName],
>		[MiddleName],
>		[LastName]
>	FROM [dbo].[Receipts]
>		INNER JOIN [dbo].[Policyheaders] ON [dbo].[Receipts].[PolicyHeaderFK] = [PolicyHeaderPK]
>		INNER JOIN [dbo].[Policies]	ON [PolicyHeaderPK] = [dbo].[Policies].[PolicyHeaderFK]
>		INNER JOIN (SELECT [PolicyHeaderFK], MAX(EffectiveDate) as EffectiveDate 
>						FROM [dbo].[Policies]
>						GROUP BY [PolicyHeaderFK]) subquery ON [Policies].[PolicyHeaderFk] = subquery.policyHeaderFK AND Policies.EffectiveDate = subquery.EffectiveDate
>		inner join [dbo].[Plans] on [PlanFK] = [PlanPK]
>		inner join [dbo].[Clients] on [ClientFK] = [ClientPK] 
>WHERE 1 = 1
>   AND ([PolicyNumber] LIKE @PolicyNumber)
>   AND ([LastName] LIKE @ClientName OR [CompanyName] LIKE @ClientName)
>   AND [ReceiptNumber] LIKE @ReceiptNumber

>
>I added this to the top:
>
>

		declare @ReceiptNumber nvarchar(20)
>		set @ReceiptNumber = NULL
>		declare @ClientName nvarchar(20)
>		set @ClientName = NULL
>		declare @PolicyNumber nvarchar(20)
>		set @PolicyNumber = 'WLIF20120047'

>
>and when I run it I get no records

No wonder. Leave only PolicyNumber condition and re-test. The NULL parameters tests should not be there.