Forms in Wordpress

Hi
Thanks for reading my post.

I am working on a Pro Bona site for a NGO and have reached the stage of developing the contact and donation forms.

I am using wordpress for their cms, I am wanting to know if I am able to code the form with form validation the same as I would for a standard php site.

Or do I have to use one of the plugin for forms.

I would naturally prefer to use the std coding for forms in php than have to use a plugin as the form has many areas that have requirements that I am not sure the plugins will handle.

Could someone please advise me on this

Thanks very much for your time and help

Mike:)

Can I customize the wordpress supplied contact form as I would customize the other pages and posts?

Is it that simple?