Javascript函数中的多个条件语句

Question

I haven't used JavaScript for sometime.

I'm trying to get this following script working so if I select "Ireland" in the dropdown, the Ireland select menu appears below. The same goes for America and Canada.

http://jsfiddle.net/mcgarriers/DPSe4/

However it's just not working. Can anyone take a look and explain why?

I'm sure it's something simple.

Many thanks for any help at all.

Answer 1

Now its working :

http://jsfiddle.net/DPSe4/3/

You needed to pass the "SELECT" node to the function , instead of the form.

Answer 2

It is because of this keyword. Inside of your function it reffers to DOM window object. Use

<select onchange='switchStates(this)'>
....

<script>
    switchStates(Sender){
       alert(Sender.selectedIndex+"-"+Sender.value);
    }
</script>

Answer 3

You're passing this.form to the function, but you've not put the parameter into the function parameter list. ie:

function switchStates( form ) {
  ...
}

Also, you're not referencing the form's select object; you need form.dcountry.selectedIndex