diff --git a/gen/ogone.py b/gen/ogone.py
index cb6c3b0..9bdf7ac 100644
--- a/gen/ogone.py
+++ b/gen/ogone.py
@@ -2,6 +2,17 @@
 import sha
 from appy import Object
 from appy.gen import Type
+from appy.px import Px
+
+view = Px('''
+<p>Hello PX world.</p>
+<x for="x in value.keys()">
+  <div if="len(x) &lt; 5">
+   <x>:x</x> : <x>:value[x]</x>
+  </div>
+  <a href=":'http://www.cetic.be/%s' % value[x]">:x</a>
+</x>
+''')
 
 # ------------------------------------------------------------------------------
 class OgoneConfig:
@@ -146,4 +157,6 @@ class Ogone(Type):
         # some URL, use it. Else, use the view page of p_obj.
         if not url: url = obj.absolute_url()
         obj.goto(url)
+
+    def getPx(self, context): return view(context).encode('utf-8')
 # ------------------------------------------------------------------------------
diff --git a/gen/ui/widgets/ogone.pt b/gen/ui/widgets/ogone.pt
index 739c32c..cb4f745 100644
--- a/gen/ui/widgets/ogone.pt
+++ b/gen/ui/widgets/ogone.pt
@@ -2,6 +2,7 @@
 <metal:view define-macro="view">
   <tal:comment replace="nothing">var "value" is misused and contains the contact params for Ogone.</tal:comment>
   <tal:comment replace="nothing">The form for sending the payment request to Ogone.</tal:comment>
+  <p tal:content="value"></p>
   <form method="post" id="form1" name="form1"
         tal:define="env value/env"
         tal:attributes="action string: https://secure.ogone.com/ncol/$env/orderstandard.asp">
@@ -13,6 +14,9 @@
     <input type="image" id="submit2" name="submit2"
            tal:attributes="src string: $appUrl/ui/ogone.gif; title python: _('custom_pay')"/>
   </form>
+  <tal:comment replace="nothing">Ogone PX test</tal:comment>
+  <div>PX</div>
+  <tal:px replace="structure python: contextObj.callField(name, 'getPx', {'obj': contextObj, 'value': value})"/>
 </metal:view>
 
 <tal:comment replace="nothing">Edit macro (none)</tal:comment>
diff --git a/pod/buffers.py b/pod/buffers.py
index 7ebf3d1..0c7df0a 100644
--- a/pod/buffers.py
+++ b/pod/buffers.py
@@ -150,7 +150,14 @@ class Buffer:
         self.write('<%s' % elem)
         for name, value in attrs.items():
             if ignoreAttrs and (name in ignoreAttrs): continue
-            self.write(' %s=%s' % (name, quoteattr(value)))
+            # If the value begins with ':', it is a Python expression. Else,
+            # it is a static value.
+            if not value.startswith(':'):
+                self.write(' %s=%s' % (name, quoteattr(value)))
+            else:
+                self.write(' %s="' % name)
+                self.addExpression(value[1:])
+                self.write('"')
         if insertAttributesHook:
             res = self.addAttributes()
         else:
@@ -605,8 +612,11 @@ class MemoryBuffer(Buffer):
                     try:
                         result.dumpContent(evalEntry.evaluate(self.env.context))
                     except Exception, e:
-                        PodError.dump(result, EVAL_EXPR_ERROR % (
-                            evalEntry.expr, e), dumpTb=False)
+                        if self.caller() == 'pod':
+                            PodError.dump(result, EVAL_EXPR_ERROR % (
+                                          evalEntry.expr, e), dumpTb=False)
+                        else: # px
+                            raise Exception(EVAL_EXPR_ERROR %(evalEntry.expr,e))
                 elif isinstance(evalEntry, Attributes):
                     result.write(evalEntry.evaluate(self.env.context))
                 else: # It is a subBuffer
@@ -621,4 +631,9 @@ class MemoryBuffer(Buffer):
     def clean(self):
         '''Cleans the buffer content.'''
         self.content = u''
+
+    def caller(self):
+        '''Returns "pod" if the caller is appy.pod, "px" if it is appy.px.'''
+        if self.env.__class__.__name__ == 'PxEnvironment': return 'px'
+        return 'pod'
 # ------------------------------------------------------------------------------