Can not call RJS and throwing error

Rails
1

I created controllers of project and task and appropraite html pages for
them and created two partials of fields and tasks and having link in
fields partial, when i call it it is throwing RJS error, please find the
code below and mention a solution for geting text box dynamically…

My Html page

<% form_for :project, :url => projects_path do |f| %>
<%= render :partial => ‘fields’, :locals => { :f => f } %>

<%= submit_tag "Create Project" %>

<% end %>

Fields Partial

<%= error_messages_for :project %>

Name: <%= f.text_field :name %>

<%= render :partial => 'task', :collection => @project.tasks %>

<%= link_to_function('Add') do |page| page.visual_effect :highlight, 'tasks' end%>

Task partial

<% @task = task %>
<%= error_messages_for :task %>

<% fields_for_task(task) do |task_form| %>

Task: <%= task_form.text_field :name %> <%= link_to_function "remove", "$(this).up('.task').remove()" %>

<% end %>

My controller

class ProjectsController < ApplicationController

def index
@projects = Project.find(:all)
end

def new
@project = Project.new
@project.tasks.build
end

def create
@project = Project.new(params[:project])
if @project.save
flash[:notice] = “Successfully created project and tasks.”
redirect_to projects_path
else
render :action => ‘new’
end
end

def edit
@project = Project.find(params[:id])
end

def update
params[:project][:existing_task_attributes] ||= {}

@project = Project.find(params[:id])
if @project.update_attributes(params[:project])
flash[:notice] = “Successfully updated project and tasks.”
redirect_to project_path(@project)
else
render :action => ‘edit’
end
end

end