st: assistance writing a loop to create a panel dataset

["tony fong" <tbfong@hotmail.com>]

Hi everyone,
I have a dataset that I need to restructure, and I'm having trouble writing 
the code that would accomplish this for me (programming is new territory for 
me). If someone could help me out on this, it'd be extremely appreciated!

My data is currently set up as such:
	+------------------------------------------------------+
	id   sch1   sch2   start1     end1   start2     end2
	------------------------------------------------------
1.	1     73      .   199308   200000        .        .
2.	2     46      .   199307   199506        .        .
3.	3     12     16   199308   199505   199508   199606
4.	4     94     58   199408   199412   199501   199606
5.	5     24      .   199608   199706        .        .
	------------------------------------------------------
6.	6     84     43   199308   199605   199608   199611
7.	7     16      .   199508   200000        .        .
8.	8     59     87   199309   199406   199609   200000
	+------------------------------------------------------+

where sch1 and sch2 represent the school ID that the teacher was teaching at 
for the respective teaching spells 1 and 2, and start1-end2 represent the 
start and end dates of spells 1 and 2,
where the first four digits is the year and the last two digits is the month 
of that year (actually my data has five possible start and end date spells, 
but it got too messy in pasting the info above).  If the end date is 200000, 
then the teacher remained at that school until the data was right-censored 
in 1998.  I've cleaned the data so that all of the spells are in order and 
none of them overlap (although there are gaps of time between some teaching 
spells).   What I'm trying to do is create a panel data set in long format, 
with one observation for each year from 1992 until 1997 for every 
individual. It would give the school that the individual taught at for each 
year (where for the year 1995, for instance, it would correspond to the 
school number that the teacher taught at for any of the months from 199507 
through 199606, inclusive), or it'd be a missing value if the teacher did 
not teach during that year since some teachers started later and many 
teachers quit after only a year or two.  I've tried to create a set of loops 
that loops through each consecutive non-missing spell to fill in the 
variables school92-school97 (which represent the school taught at for each 
year) based on the start and end dates of each spell, but I've been unable 
to do it.  Also, some teachers teach at one school for half the year and 
another school for the rest of the year -- in this case the first school 
should count for that particular year.  If anyone can help me out with the 
code that would accomplish this task it would be very much appreciated.
Thanks!
Tony


*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/