[Javascript] setting select drop selectedIndex

[Paul Novitski]

>At 10:21 AM 8/2/2006, Schalk wrote:
>>Should the following be able to set the selectedIndex of a select drop down?
>>
>>document.checkout.billingstate.options[document.checkout.billingstate.selectedIndex].value 
>>= state;

At 10:30 AM 8/2/2006, Paul Novitski wrote:

>No, that statement sets the value of the option at the selected 
>location.  I believe what you want is:
>
>         document.checkout.billingstate.selectedIndex = state;
>
>where 'state' is an integer 0-N.


I prefer to code this as:

         <select id="billingstate" name="billingstate">
         ...

                 // exit silently if it's not a DOM-enabled user agent
                 if (!document.getElementById) return;

         // find the SELECT list
         var oList = document.getElementById("billingstate");

                 // might as well abort if the markup's wrong
                 if (!oList) return alert("Fatal HTML error: 
billingstate not found");

         oList.selectedIndex = state;

This uses DOM methods and lets the program exit gracefully instead of 
simply crashing if everything isn't as it should be.

Paul