how to find only mismatched data columns in two tables

declare @mtbname1 as varchar(50)
declare @mtbname2 as varchar(50)


set @mtbname1  = 'tablename1'
set @mtbname2  = 'tablename2'



select * from (select tb.name , colum.name col  from sys.tables tb
inner join 
sys.all_columns colum on 
tb.object_id = colum.object_id  
where tb.name = @mtbname1 )tb1
left outer join   
(select tb.name , colum.name col from sys.tables tb
inner join 
sys.all_columns colum on 
tb.object_id = colum.object_id  
where tb.name = @mtbname2)tb2 
on tb1.col = tb2.col 
where tb2.col is null 

union 


select * from (select tb.name , colum.name col  from sys.tables tb
inner join 
sys.all_columns colum on 
tb.object_id = colum.object_id  
where tb.name = @mtbname1 )tb1
right outer join   
(select tb.name , colum.name col from sys.tables tb
inner join 
sys.all_columns colum on 
tb.object_id = colum.object_id  
where tb.name = @mtbname2)tb2 
on tb1.col = tb2.col 
where tb1.col is null