[Tugindia] Help

[Manjunatha G.]

Hi!
I have manually set the counter using the command in some chapter
where I need to use the equation nos. as (14.16a), (14.16b)

---
\renewcommand\theequation{14.16a}
\begin{eqnarray}
.....
\end{eqnarray}

\renewcommand\theequation{14.16b}
\begin{eqnarray}
.....
\end{eqnarray}
---
and later all the equations were numbered as (14.16b). Again
since I had only couple of equations, I have used manual numbers
using the above commands for rest of the equations in that
particular chapter.. Now, when I process the file, in chapter 15
and rest of the chapters, the last same number (14.16b) is 
repeated all over. 

Can anyone suggest me an easier way to overcome with this prob....
Thanks in advance,
Manjunath