Only sub heads should reflect column sort (and be sortable)
col 1
col 2
col 1 (sub)
col 2 (sub)
1
a
2
b
3
c
4
d
All header elements should reflect sort (and be sortable)
col 1
col 2
col 1 (sub)
col 2 (sub)
1
a
2
b
3
c
4
d
col 1
col 2
1
1 b
0.01
1 ms
1024
1 B
1
1 second
1048576
1 MB
60
1 minute
1073741824
1 GB
3600
1 hour
Date should support sorting with empty fields
col 1
1/10/2010
Jan 12, 2010
10-12-2010