Multiple set_message with min_length rule???

[eluser]123wesweat[/eluser]
Hi there,

How can i set different messages for the min_length rule??
like

Code:

$val->set_message('min_length','field X must have a min. of 5 chars')

and

Code:

$val->set_message('min_length','field Y must have a min. of 60 chars')

regards,