Make readOny a specific select (not all) in a custom form

Hi,

I’ve 4-5 selects in a custom form and i want to make readOnly or disabled just one of them. How can i do it?

I know that with the following code i can make all of them, but i need only one:

...
node.firstChild.disabled = true;
...

Thanks.

It can’t be done with default “select” block , you will need to create a custom one