How to check number of fields in form?

[andriu]

I need JavaScript function that can check by herself
how many fields are in any html form.
I want to use this function to check if at least one of all fields in form has been filled.
I also want to use one function to many forms with different
number of fields, so it should find how many of fields
is in each form.

Thanks for help.

[Khalid Ali]

alert(document.formName.length)

will display number of all elements in a form