AjaxFormSubmitBehavior and FilterForm problem

Hi,

I have a datatable inside a filterform. Everything works fine but I need to
filter table on every single typed characters in my filterform. To achieve
this I added an AjaxFormSubmitBehavior to my filterform.
There is one small problem with it. If I type one char it works fine but if
I type one and another then the first char always get selected and I can't
type other chars.
How can I get it work ?

Regards., Sandor