Stored procedure how to cater NULL condition - sql

Question

I am reading a text file as an input to execute the logic in my stored procedure following is the sample of my textfile
<tblThreatenedSpeciesSubzone>
<ThreatenedSpeciesZoneID>-1</ThreatenedSpeciesZoneID>
<ManagementZoneID>0</ManagementZoneID>
<TSSubZoneNumber>BR101_Moderate/Good_Medium_1</TSSubZoneNumber>
<TSSubZoneArea>0</TSSubZoneArea>
<AdjacentRemnantVegArea>23</AdjacentRemnantVegArea>
<PatchArea>0</PatchArea>
<CreatedBySystemUser>BBCC Training 1</CreatedBySystemUser>
<UpdatedBySystemUser>BBCC Training 1</UpdatedBySystemUser>
<SaveType>1</SaveType>
<VegetationZoneID>-1</VegetationZoneID>
<ManagementZoneName />
</tblThreatenedSpeciesSubzone>
If you noticed <ManagementZoneName /> don't have any value. In my stored procedure I tried to find if Managementzone has value or not but not sure is the right way to do
IF #ManagementZoneIDInXML > 0 and ##ManagementZoneIDInXML <> NULL
BEGIN
INSERT INTO #tblThreatenedSpeciesSubzone
(ThreatenedSpeciesZoneID,
ManagementZoneID,
VegetationZoneID,
TSSubZoneNumber,
TSSubZoneArea,
AdjacentRemnantVegArea,
PatchArea,
DateCreated,
CreatedBySystemUser,
DateUpdated,
UpdatedBySystemUser,
SaveType,
RowTimestamp)
SELECT *
FROM OPENXML (#hDoc, '/NewDataSet/tblThreatenedSpeciesSubzone', 2)
WITH (ThreatenedSpeciesZoneID INT,
ManagementZoneID INT,
VegetationZoneID INT,
TSSubZoneNumber VARCHAR(50),
TSSubZoneArea NUMERIC(9,2),
AdjacentRemnantVegArea NUMERIC(9,2),
PatchArea NUMERIC(9,2),
DateCreated VARCHAR(50),
CreatedBySystemUser VARCHAR(50),
DateUpdated VARCHAR(50),
UpdatedBySystemUser VARCHAR(50),
SaveType INT,
RowTimestamp VARCHAR(50)) XMLDATA
WHERE
ManagementZoneID = #ManagementZoneIDInXML --Only select the rows that belong to the supplied ManagementZoneID
END
ELSE
BEGIN
INSERT INTO #tblThreatenedSpeciesSubzone
( ThreatenedSpeciesZoneID ,
ManagementZoneID ,
VegetationZoneID ,
TSSubZoneNumber ,
TSSubZoneArea ,
AdjacentRemnantVegArea ,
PatchArea ,
DateCreated ,
CreatedBySystemUser ,
DateUpdated ,
UpdatedBySystemUser ,
SaveType ,
RowTimestamp )
SELECT * FROM OPENXML (#hDoc, '/NewDataSet/tblThreatenedSpeciesSubzone', 2)
WITH ( ThreatenedSpeciesZoneID INT ,
ManagementZoneID INT ,
VegetationZoneID INT ,
TSSubZoneNumber VARCHAR(50) ,
TSSubZoneArea NUMERIC(9,2) ,
AdjacentRemnantVegArea NUMERIC(9,2) ,
PatchArea NUMERIC(9,2) ,
DateCreated VARCHAR(50) ,
CreatedBySystemUser VARCHAR(50) ,
DateUpdated VARCHAR(50) ,
UpdatedBySystemUser VARCHAR(50) ,
SaveType INT ,
RowTimestamp VARCHAR(50) ) XMLDATA
WHERE VegetationZoneID = #VegetationZoneIDInXML --Only select the rows that belong to the supplied VegetationZoneID
--And no Management zone assigned
END