clearing list

[Brian]

Hi

I'm working on a site that has a form on it to do an advanced search on
a database, in the form are 2 list (<select>)

Both these list have items in them, what I want to do is if an items it
selected from list A then it sets list B value to null and of cause the
other way round. The reason is I need to make sure that when the
form is submitted I only pass an item from either list A or B not both
is I do a test on each variable to see what has been selected

I have tried onChange="this. form.town.value =''"

any ideas?

Brian

[RobG]

Re: clearing list

Brian wrote:[color=blue]
> Hi
>
> I'm working on a site that has a form on it to do an advanced search on
> a database, in the form are 2 list (<select>)
>
> Both these list have items in them, what I want to do is if an items it
> selected from list A then it sets list B value to null and of cause the
> other way round. The reason is I need to make sure that when the
> form is submitted I only pass an item from either list A or B not both
> is I do a test on each variable to see what has been selected
>
> I have tried onChange="this. form.town.value =''"
>
> any ideas?[/color]

Use an onchange function on each list that sets the other to a default
empty option (or has some value you know to ignore).

<form action="">
<select name="listA" onchange="this. form.listB.sele ctedIndex=0;">
<option selected></option>
<option value="A1">A1</option>
<option value="A2">A2</option>
</select>
<select name="listB" onchange="this. form.listA.sele ctedIndex=0;">
<option selected></option>
<option value="B1">B1</option>
<option value="B2">B2</option>
</select>
</form>



--
Rob

[Thomas 'PointedEars' Lahn]

Re: clearing list

Brian wrote:
[color=blue]
> [...] The reason is I need to make sure that when the form is submitted I
> only pass an item from either list A or B not both is I do a test on each
> variable to see what has been selected[/color]

Note that it does not work without client-side script support:
[color=blue]
> I have tried onChange="this. form.town.value =''"[/color]

If `town' is the name of a select control, this is not supposed to work.
The `value' attribute/property of those objects only specifies the selected
value. Use this instead:

var o = selectElement.o ptions;
if ((o.length = 0) > 0)
{
while (o.length > 0)
{
o[0] = null;
}
}


PointedEars
--
Let us not judge others because of their religion, color or nationality.
We are all just human beings living together on this planet. (poehoe.de)