Checking for cf nput character length

Question

I am trying to create a function that will check to see if a
<cf input type = text> is exactly 6 characters long. I need
my webpage to throw an error/popup a message when a user clicks
"Submit" and the input field has a value not equal to 6 characters.
Is this something that can be done with coldfusion or does it have
to be done purely in javascript? Any help would be appreciated.
Another concern I have is that the name of the <cfinput type =
text> is:
'ItemID#getIDDetails.ItemID#_DetailID#getIDDetails.ID#'
I'm not sure how to plug this name into a function to or
<cfif isdefined> condition. Can javascript accept an input
such as this?
Attached is the code for my <cfinput>. Also attached is
the javascript code I've been trying to program as well as a
coldfusion variant.

Answer 1

If you use cfinput, you don't need to write any javasccript
at all (CF writes it for you).
Use the following (EXACTLY) to get 6 digits required:
<CFINPUT
value = '#isSetValue#'
type = 'text'
validate = 'regular_expression'
pattern = '[0-9]{6}'
validateat = "onBlur,onServer,onSubmit"
message = 'Please enter exactly six digits for
#trim(getIDDetails.ItemName)#.'
name =
'ItemID#getIDDetails.ItemID#_DetailID#getIDDetails.ID#'
width = '50'
class = 'NewImput_no_width'
/>