XForms doubt

Hi,

I am trying to display error messages using XForms to display messages
similar to Javascript alerts. I tried <xforms:message> and <xforms:alert>.
Both didn't work.

I tried the example below:

<xforms:trigger>
<xforms:label>OK</xforms:label>
<xforms:message level="modal" ev:event="DOMActivate">You clicked
me!</message>
</xforms:trigger>

It is working fine for me. But I want to display an error message when the
user types something in a text box (<xforms:input>) and takes the focus out
of that text box(DomFocusOut). For example, I want to display the text
"Please enter a positive integer" when the user types in the text box
and the focus is changed from the text box. I have given <xforms:bind> for
that text box reference with type="xs:positiveInteger". It shows a red
exclamation mark for invalid entries. But I want to display my custom text
in a pop up window.

Can some one please help me?

Many Thanks
Merin