simple: modifying label text elp?

[vector]

this should be easy for all you pythonettes.
i cant modify my label text.

i have an entry widget and simply saying
w.insert(0,"new text")
works like a treat
ie i have set up textvariable etc when making the entry.
i used eactly the same setupcode but with label
and it dosnet work
first of all,error- no insert on label widgets. allowed
i read the guff and i think im supposed to use
w.setvar(name='myvar',value='new text')
no errors report but the label text dont change either:(