scripts in RoR

i want to use scripts in my program.how can i write a script ? where
it should be write in application.js and how.?and how can i call it

i want to use scripts in my program.how can i write a script ? where
it should be write in application.js and how.?

app,ication.js is a good place for some general purpose scripts,
that are used by all (or most) of your views
don't forget to use:
  <%= javascript_include_tag :defaults %>
in the header section of your layout

but you can use your own js files as well, place them in public/
javascripts
and (assuming myscripts.js is the filename:
  <%= javascript_include_tag 'myscripts' %>

and how can i call it
from my view..can anybody help me with some simple examples.

say you have defined a js function like
function doSomething() {
  alert('hello world');
}

in a file & included it as described above, then it will be available
as any js from your page. There are many ways to call this function
for

one of the most simple:
<%= link_to_function("hello", "doSomething()") %>

will create a link and call this function.
But you can use it as event handler in onclick, call it directly from
any other function
and so on.