Remove empty values from DropDown menu

[Anon]

I have created a PHP script that enables me to display 2 drop down lists, and in the second one, you get the results based on a the selection you made in the first one.
So this works with Javascript and the "onchange" thing.

To that end, I am obliged to:
1) create the pre-filled 1st drop down menu
2) create an EMPTY 2nd drop down with a pre-determined number of potential values (let's say 15)
3) make an update function (containing the javascript)

My problem is the following:
Depending on the selection made, there will be empty values in the second drop down.
F.e. if there are 7 results, they will be followed by 8 empty results.

How can I remove these empty "rows" dynamically?

Thanks in advance!

[dzekic]

You can use javascript propery "length" of "SELECT" object. You just assign value of wanted number of the "OPTION" objects under your "SELECT" object.

e.g.:
document.forms[0].MultipleChoice.length = 3

This line will cause only first 3 "OPTION" objects to be shown.