Question

It seems this ought to be dead simple, but I’m stuck. I’ve written some asp.net code that outputs a pair of radio buttons:

<p>
<label for='chkYapper'>Yapper</label>
<input type='radio' name='yapper' id='chkYapper' value='yapper' checked='<%=gblYapperChecked %>' />
<br />
<label for='chkNonYapper'>non-Yapper</label>
<input type='radio' name='Yapper' id='chkNonYapper' value='nonYapper' checked='<%=gblNonYapperChecked %>' />    

        if (registrationUser.isYapper == 1)
        {
            gblYapperChecked = "checked";
            gblNonYapperChecked = "";
        }
        else
        {
            gblYapperChecked = "";
            gblNonYapperChecked = "checked";
        }

As expected, I get two radio buttons, “Yapper” and “Non-Yapper”. However, even when I step thru my code and see that gblYapperChecked is “checked” and gblNonYapperChecked is “”, Non-Yapper is always selected by default in the web browser.

What am I doing wrong?

UpdateHere is the HTML code as it actually appears in the browser. “Yapper” should be selected, but “Non-Yapper” appears selected instead.

<p>
<label for='chkYapper'>Yapper</label>
<input type='radio' name='yapper' id='chkYapper' value='yapper' checked='checked' />
<br />
<label for='chkNonYapper'>non-Yapper</label>
<input type='radio' name='yapper' id='chkNonYapper' value='nonYapper' checked='' />    

Answer 1

Note that the HTML “checked” attribute is generally determined by being present or not present. See http://www.w3.org/TR/html401/interact/forms.html#adef-checked for the spec.

In particular what this means is that if you want it to be checked you cna have checked, checked=true, checked=checked and so on. So what you want is to not have the checked attribute at all if you don’t want the checkbox selected.

I would advise structure such as:

<input type='radio' name='Yapper' id='chkNonYapper' value='nonYapper' <%=registrationUser.isYapper?"":"checked='checked'" %> />

This should eliminate your checked attribute entirely dependant on your isYapper boolean.