Joomla2.5.14 Server Side Validation for Login Page

[Manan]

I am using Joomla2.5.14 and I want to add some more server side validation like:

a) Please enter your email address. (Outline email address box in red).
b) Your email address is not registered with Us. (Outline email address box in red).
c) Your email address is invalid. (For invalid email address which is different from registered email address - Outline email address box in red).
d) Please enter your password. (Outline password box in red).
e) Your password is incorrect. (Outline password box in red).

in Joomla login page.

For my project I have added "awoelogin" to login with email address.

Can somebody guide me where to apply changes in Joomla files. I want to show error like this style (http://docs.joomla.org/Display_error_me ... nd_notices).

Currently I am getting only one error. (Check my attachment)

Thanks