title: openerp Message_post error..NameError: global name '_' is not defined
body: <p>I have created a custom module with chatter in the form.</p>
  
  <p>I want to post a custom message. but I am getting following error.</p>
  
  <pre><code>File "/opt/openerp/my_modules/forum/forum.py", line 22, in function_which_post_msg
      self.message_post(cr, uid, ids, body=_("New Question has been &lt;b&gt;created&lt;/b&gt;"), context=context)
  NameError: global name '_' is not defined
  </code></pre>
  
  <p>my .py file is</p>
  
  <pre><code>import datetime
  import time
  import openerp
  from openerp.osv import osv, fields
  
  
  class Course(osv.osv):
      _name = "forum.course"
      _inherit = ['mail.thread', 'ir.needaction_mixin']
  
      _columns = {
                'name' : fields.char(string="Question Title", size=256, required=True),
                'description' : fields.text(string="Question Description", required=True),
  
                 }
  
  
      def function_which_post_msg(self, cr, uid, ids, context=None):
          self.message_post(cr, uid, ids, body=_("New Question has been &lt;b&gt;created&lt;/b&gt;"), context=context)
  
      def create(self, cr, uid, ids, context=None):
          self.function_which_post_msg(cr, uid, ids, context=context)
  </code></pre>