form validation, showing form_error()

[eluser]Krystian[/eluser]
please look at the example code

Code:

<div id="form_error">

echo form_error('field1');
echo form_error('field2');

</div>

the problem is when I styled this div with colors and background it is visible all the time without error message.
The question is how to check if any errors occured?
the whole div could be putted into if condition