[Javascript] Javascript - Form value undefined

Tim Makins spindrift at oceanfree.net
Tue Nov 11 01:21:59 CST 2003


----- Original Message -----
From: "Tim Burgan" <lists.latech.edu at greaterthani.com>
To: "[JavaScript List]" <javascript at LaTech.edu>
Sent: Tuesday, November 11, 2003 7:04 AM
Subject: [Javascript] Javascript - Form value undefined


> <http://www.greaterthani.com/05_programming/week5help.htm>
>
> The form with the radio button displays a result of 'undefined', when it
> should be either 0 or 0.25
>
> Can someone please take a look at this to kelp me out?


Always happy to kelp out if I can !

You can't read radio values like that. You must see if they are checked or
not first.
Look at the script below (not mine)

Tim in Ireland.

<html>
<head>
<title>Listing 28.7. Finding the Activated Radio Button In a Group</title>

<script language="JavaScript" type="text/javascript">
<!--

function radio_active(radio_group) {

    // Run through the group
    for (counter = 0; counter < radio_group.length; counter++) {

        // When we find the activated button, return the index
        if (radio_group[counter].checked) {
            return counter
        }
    }
    // If no button is activated, return -1
    return -1
}

function display_radio_value(current_form) {

    // Get the index of the activated button
    var radio_index = radio_active(current_form.freight_group)

    // If a button is activated, display its value in the text box
    if (radio_index >= 0) {
        current_form.selected_radio.value =
current_form.freight_group[radio_index].value
    }
}

//-->
</script>

</head>

<body>

<form>

<input type="radio" name="freight_group" value="FedEx" checked>Federal
Express
<br>
<input type="radio" name="freight_group" value="UPS">United Parcel Service
<br>
<input type="radio" name="freight_group" value="Airborne">Airborne Express
<br>
<input type="radio" name="freight_group" value="Mail">Surface Mail
<br>
<input type="text" name="selected_radio">
<br>
<input type="button" value="Display Active Radio Value"
onClick="display_radio_value(this.form)">

</form>

</body>
</html>










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