Select control question in Javascript

[Carl Wu]

Hi all,

I am newcomer in HTML, Javascript,

I want to create two select controls S1, S2.

There are 3 options: ALL, A, B in S1;

When select A in S1, It let you select A1, A2 in S2,

Where select B in S1, It let you select B1, B2 in S2;

When select ALL in S1, It let you select A1, A2, B1, B2 in S2

The default selection in S1 is ALL,

Can somebody give me some suggestion?

Thanks advance

Carl

[Thomas 'PointedEars' Lahn]

Carl Wu wrote:

I want to create two select controls S1, S2.
<select name="S1">
</select>

<select name="S2">
</select>
There are 3 options: ALL, A, B in S1;
<select name="S1">
<option>ALL</option>
<option>A</option>
<option>B</option>
</select>
When select A in S1, It let you select A1, A2 in S2,

Where select B in S1, It let you select B1, B2 in S2;

When select ALL in S1, It let you select A1, A2, B1, B2 in S2
<script type="text/javascript" language="JavaScript">
<!--
function enableItems(o)
{
if (!o || !o.form || !o.form.elements)
return false;

var
o2 = o.form.elements['S2'],
a1 = o2.options[0],
a2 = o2.options[1],
b1 = o2.options[2],
b2 = o2.options[3];

if (o2 && a1 && typeof a1.disabled != "undefined")
{
switch (o.selectedIndex)
{
case 0: // ALL
a1.disabled = false;
if (a2)
a2.disabled = false;
if (b1)
b1.disabled = false;
if (b2)
b2.disabled = false;
break;

case 1: // A
a1.disabled = false;
if (a2)
a2.disabled = false;
break;

case 2: // B
if (b1)
b1.disabled = false;
if (b2)
b2.disabled = false;
}
}
}
//-->
</script>
<form action="...">
<select name="S1" onchange="enableItems(this)">
<option>ALL</option>
<option>A</option>
<option>B</option>
</select>

<select name="S2">
<option>A1</option>
<option>A2</option>
<option>B1</option>
<option>B2</option>
</select>
</form>

Untested.
The default selection in S1 is ALL,
It is the default because it is the first item.
Can somebody give me some suggestion?

See above. And before you post to a newsgroup the next time, you should get
a minimum clue of what you are doing (by reading documentations, FAQS aso.)
This is not a support forum but a discussion group.
PointedEars