[xsl] Inverting names with Jr and Sr considered

["Mark" <mark@xxxxxxxxxxxx>]

This must have been done many times, so can some one show me where to find 
the answer?

I have a series of personal names in natural order that I need to invert. 
The surname is always last except when followed by bJrb, or bSrb (either of 
which may not be present). I want to represent:

J Allen Rogers b> Rogers, J Allen
Bill T Wilson Jr b> Wilson, Bill T (Jr)
A B Brown b> Brown, A B
John Victor Case Sr b> Case, John Victor (Sr)

and so on. There may be a single space or multiple spaces between some the 
elements of the name.

It looks like <xsl:analyze-string> will do this, but I do not know how to 
write regex.

Thanks,
Mark