Selecting Null Values

I have a stored procedure that allows users to select addresses based on partially supplied information from the user.  My procedure seems to work fine in all but a few cases. If a user decides to select all the rows for a particular country the procedure below does not return any rows even if the rows exist.  I tracked this down to the fact that for Non US countries I set both the StateCode and Country Code to nulls. .

 Below is a partial version of my code.  Can anyone show me how I can do a "Like" Search even if some of the fields in the row contain null values?

Thanks

 1 CREATE PROCEDURE dbo.Addresses_Like( @SendTo VarChar(50) = Null
2 , @AddressLine1 VarChar(50) = Null
3 , @AddressLine2 VarChar(50) = Null
4 , @City VarChar(50) = Null
5 , @StateCode VarChar(2) = Null
6 , @ZipCode VarChar(10) = Null
7 , @CountryCode VarChar(2) = Null)
8
9
10 Declare @SearchSendTo VarChar(50)
11 Declare @SearchAddressLine1 VarChar(50)
12 Declare @SearchAddressLine2 VarChar(50)
13 Declare @SearchCity VarChar(50)
14 Declare @SearchStateCode VarChar(2)
15 Declare @SearchZipCode VarChar(10)
16 Declare @SearchCountryCode VarChar(2)
17
18 If (@SendTo Is Null)
19 Set @SearchSendTo = ""
20 Else
21 Set @SearchSendTo = @SendTo
22
23 If (@AddressLine1 Is Null)
24 Set @SearchAddressLine1 = ""
25 Else
26 Set @SearchAddressLine1 = @AddressLine1
27
28 If (@AddressLine2 Is Null)
29 Set @SearchAddressLine2 = ""
30 Else
31 Set @SearchAddressLine2 = @AddressLine2
32
33 If (@City Is Null)
34 Set @SearchCity = ""
35 Else
36 Set @SearchCity = @City
37
38 If (@StateCode Is Null)
39 Set @SearchStateCode = ""
40 Else
41 Set @SearchStateCode = @StateCode
42
43 If (@ZipCode Is Null)
44 Set @SearchZipCode = ""
45 Else
46 Set @SearchZipCode = @ZipCode
47
48 If (@CountryCode Is Null)
49 Set @SearchCountryCode = ""
50 Else
51 Set @SearchCountryCode = @CountryCode
52
53
54 Select AddressID
55 , SendTo
56 , AddressLine1
57 , AddressLine2
58 , City
59 , StateCode
60 , ZipCode
61 , CountryCode
62 , RowVersion
63 , LastChangedDateTime
64 , OperID
65 From Addresses
66 Where SendTo Like RTrim(LTrim(@SearchSendTo)) + "%"
67 And AddressLine1 Like RTrim(LTrim(@SearchAddressLine1)) + "%"
68 And AddressLine2 Like RTrim(LTrim(@SearchAddressLine2)) + "%"
69 And City Like RTrim(LTrim(@SearchCity)) + "%"
70 And StateCode Like RTrim(LTrim(@SearchStateCode)) + "%"
71 And ZipCode Like RTrim(LTrim(@SearchZipCode)) + "%"
72 And CountryCode Like RTrim(LTrim(@SearchCountryCode)) + "%"
73 Order By CountryCode, City, AddressLine1, AddressLine2, SendTo