selectedIndex doesn't change?

JavaScript
1

Hi I have the following code, it is supposed to add an option to op4 if the selectedIndex of op2 is 0 and the value of op1 is “blah blah”

Point is, it adds a new option every time, and it’s because the selectedIndex of op2 doesn’t change.


function setJign()
{
var op1 = document.poles.op1;
var op2 = document.poles.op2; 
var op3 = document.poles.op3;
var op4 = document.poles.op4;

var $t = op1.options[op1.selectedIndex];
var $v = op2.selectedIndex;
	if($v = "0")
	{
		if($t = "Jig N Pole - $24.00")
		{
			op4.options[op4.options.length] = new Option('Cork Handle - $1');
			alert($v);
		}
	} else {
		op4.options.length = 0;
		op4.options[op4.options.length] = new Option('EVA Foam - $0');
	}
}

The problem is that the selected index, as reported by the function, doesn’t change.

Firebug says that the selectedIndex changes, but the function doesn’t

Here is a link to the site
http://www.slatersjigs.com/crappie_poles/crappiepoles.php

Please be gentle on the code, I’m new.

Thanks in advance for the help!

2

You are using assignments (=) instead of equality comparisons (==). That’s most likely your problem.

Change to,

if($v == "0")

and

if($t == "Jig N Pole - $24.00")
3

Thanks, can’t believe I didn’t see it.

Also just out of curiosity now, how can you get the value of a selected option?

4

Normally as sel.options[sel.selectedIndex].value or simply as sel.value (where sel is a reference to the <select> element).

5

Does that update after the page loads?

Such as if I got the value after it had been changed, would it reflect the change or just give me what was originally the value?

6

It gives you the value of the option that is selected when you execute the statement. If you assign the value to a variable, that variable will not change to reflect changes made on the page. But the statement itself (e.g., sel.value) always returns the currently selected value.

7

Thanks again for the help!