why can't recognize index in hidden variable

[john woo]

Hi

I got a question in a form. that's:

<TABLE WIDTH="100%" BORDER=0><TD align="Left" width="19%" >
<select name="DEPARTMENT" SIZE ="1" style="width:200px;"
onChange="Change()">
<option value="0"> &lt;ALL&gt
<option value="1000012" >Food Sales
....
</select>
</TD>

<FORM name="InputForm" id="InputForm" method="post" action="url">
<INPUT TYPE="HIDDEN" NAME="DEPARTMENT" VALUE="">

function Change()
{
var selIndex = document.InputForm.DEPARTMENT.selectedIndex;
alert("****" + selIndex + "***");
var selValue =
document.InputForm.DEPARTMENT.options[selIndex].value;


the question is, why the pop up message always says ***undefined***
whenever a change to the selection?

It should indentify the selected index, right?

Can any one point it out?

 

[Joakim Braun]

Hi

I got a question in a form. that's:

<TABLE WIDTH="100%" BORDER=0><TD align="Left" width="19%" >
<select name="DEPARTMENT" SIZE ="1" style="width:200px;"
onChange="Change()">
<option value="0"> &lt;ALL&gt
<option value="1000012" >Food Sales
...
</select>
</TD>

<FORM name="InputForm" id="InputForm" method="post" action="url">
<INPUT TYPE="HIDDEN" NAME="DEPARTMENT" VALUE="">

function Change()
{
var selIndex = document.InputForm.DEPARTMENT.selectedIndex;
alert("****" + selIndex + "***");
var selValue =
document.InputForm.DEPARTMENT.options[selIndex].value;


the question is, why the pop up message always says ***undefined***
whenever a change to the selection?

It should indentify the selected index, right?

No, it shouldn't. A hidden field has no selected index. And the hidden field
of the form "InputForm" is what your code accesses.

 

[john woo]

Thanks lots.

one more question, if the form in above code is included from others,
how can I overwrite the accessiblity of the variable in that form?

 

[Mick White]

john woo wrote:
[..]

<select name="DEPARTMENT" SIZE ="1" style="width:200px;"
onChange="Change()">
<option value="0"> &lt;ALL&gt
<option value="1000012" >Food Sales
...
</select>
</TD>

<FORM name="InputForm" id="InputForm" method="post" action="url">
<INPUT TYPE="HIDDEN" NAME="DEPARTMENT" VALUE="">

function Change()
{
var selIndex = document.InputForm.DEPARTMENT.selectedIndex;
alert("****" + selIndex + "***");
var selValue =
document.InputForm.DEPARTMENT.options[selIndex].value;


the question is, why the pop up message always says ***undefined***
whenever a change to the selection?

It should indentify the selected index, right?

Can any one point it out?

Your select object appears to be outside of your form, and your hidden
field object should have a unique name.

Mick