[Tugindia] eqnarray and text alignment

[Ashis Kumar Mal]

Hello,
I wish to format the following maths equations seperated by text 
such as:

        x=y+1
and 
	z=y-1

using eqnarry environment.
I tried this code.

\begin{eqnarray}
&x&=y+1\\
and&& \notag\\
&z&=y-1
\end{eqnarray}

The results are NOT at all good. I wanted to have "and" left aligned.

Could somone suggest a better way.

Best.
-Ashis
Kharagpur