Dependent custom select fields?

[CiviFan2]

Have been looking around, but can't find how I can make fields dependent on each other of otherwise create the following.

For events I want participants to register certain attendance preferences in order (1st pref, 2nd pref, 3rd pref, etc.), but of course cannot have the same preference three times (as this will make proper scheduling impossible). So would want to run a simple check before registering whether they filled in the same preference more than once.

Any thoughts? would assume this to be a simple, field can not have same value as other field....

Thanks!

[Erik Hommel]

No standard option as far as I know, you will to use a validateForm hook?

[Donald Lobo]

i suspect you can accomplish this by adding a small bit of jQuery code to check for equal field values before form submission (or on field entry)

lobo