Form Input Enable/Disable

[hybrid kill3r]

I'm trying to make a form, one field has two radio input options, another is a text input. The first field asks a question and has the options of Yes or No. The text input that comes after it should only be enabled if the user selects the Yes option. How do I do this with this bit of code?

<script type="text/javascript">function disable_enable(){if (document.all || document.getElementById){if (document.register.clanpass.disabled==true)document.register.clanpass.disabled=falseelsedocument.register.clanpass.disabled=true}}</script>

[Reg Edit]

I'm trying to make a form, one field has two radio input options, another is a text input. The first field asks a question and has the options of Yes or No. The text input that comes after it should only be enabled if the user selects the Yes option. How do I do this with this bit of code?

<script type="text/javascript">function disable_enable(){if (document.all || document.getElementById){if (document.register.clanpass.disabled==true)document.register.clanpass.disabled=falseelsedocument.register.clanpass.disabled=true}}</script>

I would use document.getElementById to reference the element:

if (document.getElementById('clanpass').disabled==true)document.getElementById('clanpass').disabled=falseelsedocument.getElementById('clanpass').disabled=true

Also, I would simplify the code by making use of the fact that the value of the disabled attribute value is already boolean true/false. This means you can have a single statement instead of an if/else:

document.getElementById('clanpass').disabled=(!document.getElementById('clanpass').disabled)

[Reg Edit]

Sorry, realised after posting, your question was to do with the radiobuttons, which your function doesn't refer to yet! There are various ways to check which radiobutton is checked, but assuming you have radiobuttons such as:

<input type="radio" name="r" value="yes" checked="checked" onclick="disable_enable(this)">Yes<input type="radio" name="r" value="no" onclick="disable_enable(this)">No

then the javascript could become:

function disable_enable(radio){   document.getElementById('clanpass').disabled=!(radio.value=='yes');}