prepopulate radio button

[tableman]

This script prepopulates select box, state, but not radio button, tobacco.

<script language="javascript" type="text/javascript">

function prepop()
{
document.long_form.state.value="<?php echo $_SESSION['state']; ?>";
document.long_form.tobacco.value="<?php echo $_SESSION['tobacco']; ?>";
}
window.onload=prepop;

</script>

The value for tobacco, yes or no, shows on the page with view source, so it got to the page, but I can't find how to address a radio button so the value is preselected, and I'm out of ideas.

Any suggestions?

[jimfraser]

document.long_form.tobacco.checked = true;

[tableman]

Thanks for your reply, jimfraser.

Adding that line to the javascript made no difference.

Is there something else that should be done?

[felgall]

It should be:

document.long_form.tobacco[0].checked = true;

or if that doesn't check the right one then change the number between the [] to one less than the one that should be checked.

[tableman]

Thank you, felgall.

Now at least one of the buttons shows as being checked on the receiving page.

However, whether it should be yes or no depends on what the visitor checks in the first (short) form. The value is being passed for visitor convenience in case they also want to complete the long form.

The value is received using

document.long_form.tobacco.value="<?php echo $_SESSION['tobacco']; ?>";

so somehow that value needs to be specified.

I tried a few alternatives based on your suggestion, but none have worked so far.

[felgall]

Try this (not sure if it will work and not where i can test it at the moment):

document.long_form.tobacco["<?php echo $_SESSION['tobacco']; ?>"].checked = true;

[tableman]

felgall, that was one of the alternatives I had tried.

It does not work because the value it delivers is either 'yes' or 'no' whereas the value needs to be either '0' or '1'' as explained in your previous reply.

Here is the solution:

var tob;
var tabac="<?php echo $_SESSION['tobacco']; ?>";
{
if (tabac=="yes")
{tob="0"}
else if (tabac=="no")
{tob="1"}

document.long_form.tobacco[tob].checked = true;

Thanks for starting me on the right track.

Resolved!