numeric form validation does not work

[eluser]phpfresher[/eluser]
I also having the similar problem in password and confirm password field . But i solve it in a different way.
User the callback function .

Code:

$this->form_validation->set_rules('espresso', 'Qty', 'trim|numeric');

to

Code:

$this->form_validation->set_rules('espresso', 'Qty', 'trim|callback_numeric_check');  

function numeric_check($num){
if(!isset($num)){
   return false;
}
perform the numeric check .. or paste the code from form_validation library into it.
}

But it is not the actual solution but its the last solution. Actually numeric would work. But in case if you cant solve the problem follow the above approach.