You likely have a block like this in your create/update methods:
respond_to do |format|
if @post.save
format.html { redirect_to(@post, :notice => 'Post was successfully created.') }
format.xml { render :xml => @post, :status => :created, :location => @post }
else
format.html { render :action => "new" }
format.xml { render :xml => @post.errors, :status => :unprocessable_entity }
end
end
So if your instance variable is named @post, and it's redirecting to the show view for the post after it saves, all you have to do is change the "redirect_to(@post, ..." part to whatever you want. Say you wanted to redirect to the root of your site - you could instead have
redirect_to(root_path, :notice => 'Post was successfully created.')
In your particular case, you could use something like this if you have your routes set up:
redirect_to(payment_page_path(@post), :notice => 'Post was successfully created.')
Hope that helps!