Save URL parameter when $this -> form_validation -> run() == FALSE

[eluser]Unknown[/eluser]
Hi people.

I have a question about form validation process, I have a function where I recive a parameter but when there is any validation error in the form it's load the vew again showing the error, but I lost the parameter value.

for example localhost/controller/function/parameter.
$this -> form_validation -> run() == FALSE redirects me to localhost/controller/function/ without the parameter.

Any suggestiones?

Thanks a lot for your help.