I've got a page which is part of a book ordering system. On this page, the user can select a book either by Title or ISBN. I have two drop-down <SELECT> menus which are populated with these two lists.

So far so good.

Now, when the user makes a choice from one, I need the other to automatically change to reflect the same choice. I have the onchange() set up ok, but how do I change the currently selected VALUE in the other list? I can easily set it up if I know that I want, say the fifth item selected, but how do I select the correct <OPTION> by value?

As always, TIA