Rexx/Tk

I have a little simple rexxtk window with 2 buttons and
an entry field. Everything works as I expect except for
some of the niceties:

1) HOW to I force the cursor to be in the entry field? If
I tab once it appears, but how do I default it to the
entry field?

2) HOW do I provide an initial value in the entry field?

3) How do I position the window on the screen? It
appears in a couple different places, but I wouold like
some control over where it appears when it is invoked.

The entry definition is:
entry = TkEntry('.e1', '-width', 12, '-font', 'Arial 24 bold',,
'-text', 'fred',,
'-bg', 'lightgreen', '-fg', 'darkgreen')
text is ignored...
Help?