how can i add a count like this
eg:- there is a five digit no in the table field ,
when form loads the five digit no has to add(+) a nother one then 00001+1=00002

eg Code:-

strlastno = rstserial.Fields("LastNo")
strlastno = Val(strlastno) + Val(1)

from this statement it has to done upto 00009 then after this cant be done


after that five digit number come to 00009 then
it will be generate a error dulicating the database

how can i do this count

pleace help me