how to move your button depends on how your button is
positioned. if it is inside a table cell, you can use
style="padding:200px;" in that cell (change the value of padding as
you need + look up stylesheets if you have no idea what i am
talking about.
if your button is not inside a table cell, but in a paragraph
tag, use same in the <p>. if you are using rich forms, then
it's a very different issue...
as for form validation, first step will be to google
"javascript form validation +tutorial" and read as many results as
you can. when you are somewhat familiar with the basics, start
looking up code on free code sites like dynamicdrive.com and
figuring out how they work and adapting it to your needs. buy some
books, too.