value of radio button if not selected...

booboo0912 · Jul 9, 2003

If a user doesn't choose a value from a list of radio buttons, the value sent to the database is 'undefined'. I'm trying to check to see if the value of the radio button is null/blank/undefined, and if it is, to change the value being sent to the database to 'n/a' or something similar, anything but 'undefined'. This has to be a simple fix, but I can't figure it out...is it Friday yet????

Anyone out there know the solution?
Thanks in advance!

dwarfthrower · Jul 9, 2003

Put an extra radio button in your group with a value of 'n/a' or whatever you want and set it to be selected by default. That way if the user neglects to change it there will be a sensible value passed back to the server.

grtfercho · Jul 10, 2003

This is what happens with radio sets and Checkboxes.
If you don't select anything nothing ,not even the name of the <input> gets passed.
This is different from textareas, select and text boxes where if you don't type anything just a blank value is passed(but at least the name gets created).

For example if you had a textbox [txtinput] and a radio group [radinput] and you dont select anything on the group and don't type anything on the box when you submit the form you will get something like filename.xxx?txtinput=

Now you can do two things.
On the client side: have a default value on the radio group so you are always sure you are passing something.
On the server side : check for the existence of the variable and if doesn't exist then assign a default value before processing on SQL statement.
for example: Cold Fusion has a handy way of checking for these kind of things <CFPARAM >

I don't know what language you are using but certainly there's got to be a way of checking for this things .

good luck

grtfercho çB^]\..
"Imagination is more important than Knowledge" A. Einstein

booboo0912 · Jul 10, 2003

Thanks to you both for your replies!!!

Using a radio button with a default value (n/a) is preferred, although that radio button would have to be hidden from the user...which wouldn't be a bad thing.

grtfercho, I've been trying to check for the existence of the variable before submitting to the database. I'm using a Javascript function to set the value to 'n/a' if a value doesn't exist, but I can't figure out the correct value to check for, ie,

if((value == null) || (value == ' ')) {
document.form.radiobttn.value = 'n/a'
}

the values (null & blank) aren't correct...I know the field is blank/undefined...but how do I check for that??

Thanks again to you both!!

grtfercho · Jul 10, 2003

You have to use a loop and see the value of the 'checked' property.

here's another quick solution.
have a hidden field with the name of your column in the table.
every time you check on a radio have a function that updates the hidden element if nothing gets selected the original value of the hidden field (ie 'n/a') gets passed.

<script>
function changeField(elem,txtname){
var txtelem=eval('document.'+elem.form.name+'.'+txtname);
txtelem.value=elem.value;
alert('Current hidden Value : '+txtelem.value) //this is for debugging only feel free to delete the line.
}

</script>

<body>

<form action="actiontest.html" name="testform">
<input type="hidden" name="txtfield" value="n/a">
<input type="radio" name="radfield" onclick="javascript:changeField(this,'txtfield');" value="Cars">
<input type="radio" name="radfield" onclick="javascript:changeField(this,'txtfield');" value="Motorcycles">
<input type="radio" name="radfield" onclick="javascript:changeField(this,'txtfield');" value="Planes">
<input type="radio" name="radfield" onclick="javascript:changeField(this,'txtfield');" value="Boats">
</form>
</body>

grtfercho çB^]\..
"Imagination is more important than Knowledge" A. Einstein

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value of radio button if not selected...

booboo0912

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dwarfthrower

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grtfercho

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booboo0912

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grtfercho

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