option select in javascript`

sand133 · Jul 9, 2005

hey guys,

i have the following code that outputs a drop down. however in javascript how can i set the the value of the drop when a user selects a button.

<SELECT NAME="partnumber">
<OPTION VALUE="7382">steam turbine
<OPTION VALUE="2928">resistor array
<OPTION VALUE="3993">widget analyzer
<OPTION VALUE="9398">fiber identifier
</SELECT>

thanks guys

tsdragon · Jul 9, 2005

Code:

document.forms["myForm"].elements["dropDown"].value = someValue;

Tracy Dryden

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard. [dragon]

sand133 · Jul 9, 2005

hey tsdragon thanks for that but i was wondering if you could give me an example, im new to Javascript.

oh if you know of any good javascript tutorial site let me know

thanks

tsuji · Jul 9, 2005

[1] The question is not very clear to start with.
[2] The "value" of the select-tag is not rightaway intuitive.
[2.1] It is read-only (ff/nn) or
[2.2] It's got ignored if being assigned a value attribute on select-tag (ff/nn/ie); and
[2.3] if write something to it dynamically, it either ignores it (ff/nn) or disturbes the select index to being -1 (nothing selected, ie).
- tsuji

shu745 · Jul 11, 2005

This should do it.
===========================================
<html>
<head>
<script>
function setListValue(val){
document.partNumberForm.partnumber.value=val;
}
</script>
</head>
<body>
<form name="partNumberForm">
<table>
<tr>
<td align="center">
<SELECT NAME="partnumber">
<OPTION VALUE="-1">select part number
<OPTION VALUE="7382">steam turbine
<OPTION VALUE="2928">resistor array
<OPTION VALUE="3993">widget analyzer
<OPTION VALUE="9398">fiber identifier
</SELECT>
<br /><br />
<button onClick="setListValue('7382');">steam turbine</button> 
<button onClick="setListValue('2928');">resistor array</button> 
<button onClick="setListValue('3993');">widget analyzer</button> 
<button onClick="setListValue('9398');">fiber identifier</button>
</td>
</tr>
</table>
</form>
</body>
</html>
===========================================
- shu

tsuji · Jul 11, 2005

Glad shu745 bring this up again.

Upon re-reading my post above, I was not summing up the issue very clearly and in exact terms.

You sure can "write" the available option value to a select element. But what I was trying to express is that you cannot write whatever to it. Furthermore, if you write whatever freely to it, browsers behaves differently. Msie will show you nothing selected (selectedIndex=-1), whereas mozilla will just ignore what you've "written" to it.

If what written is intended to change a particular option value individually, you have to delete it and insert a new Options to it and not just write something to it.

Another morbid case is if we casually do anything non-sensical like <select name="..." value="shouldnotbehere">, that "value" attribute will be ignored as out-of-place.

- tsuji

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option select in javascript`

sand133

Programmer

tsdragon

Programmer

sand133

Programmer

tsuji

Technical User

shu745

Programmer

tsuji

Technical User

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