title: Warning message not working on openerp
body: <p>I want to show a warning message in user interface side in my module in a particular condition.For that I have write the code like this.</p>
  
  <pre><code>raise osv.except_osv(('Warning!'), ("Entered Quantity is greater than quantity on source."))
  </code></pre>
  
  <p>But in that condition in user interface side it just showing the loading image.</p>
  
  <p>At the console I got the error like this.</p>
  
  <pre><code>2013-06-10 09:45:53,612 364
  ERROR None openerp.netsvc: Warning! Entered Quantity is greater than quantity on source.
  Traceback (most recent call last):
     File "C:\OpenErp\openerp\openobject-server\openerp\netsvc.py", line 361, in dispatch_rpc
       result = ExportService.getService(service_name).dispatch(method, params)
     File "C:\OpenErp\openerp\openobject-server\openerp\service\web_services.py", line 585, in dispatch
       res = fn(db, uid, *params)
     File "C:\OpenErp\openerp\openobject-server\openerp\osv\osv.py", line 167, in execute_kw
       return self.execute(db, uid, obj, method, *args, **kw or {})
     File "C:\OpenErp\openerp\openobject-server\openerp\osv\osv.py", line 121, in wrapper
       return f(self, dbname, *args, **kwargs)
     File "C:\OpenErp\openerp\openobject-server\openerp\osv\osv.py", line 176, in execute
       res = self.execute_cr(cr, uid, obj, method, *args, **kw)
     File "C:\OpenErp\openerp\openobject-server\openerp\osv\osv.py", line 164, in execute_cr
       return getattr(object, method)(cr, uid, *args, **kw)
     File "C:\OpenErp\openerp\openobject-addons\mat_mgmt\mat_mgmt.py", line 101, in button_confirm
       raise osv.except_osv(('Warning!'), ("Entered Quantity is greater than quantity on source."))
  except_osv:
    ('Warning!', 'Entered Quantity is greater than quantity on source.')
  c:\openerp\openerp\openobject-addons\mat_mgmt\mat_mgmt.py(101)button_confirm()
  -&gt; raise osv.except_osv(('Warning!'), ("Entered Quantity is greater than quantity on source."))
  </code></pre>
  
  <p>I want to show the warning message on user interface side.</p>