I want to determine if a radio button has been selected. FF and Safari evaluate this differently.

for (i = 0; i < document.forms[0].RadioButtonName.length; i++)
{
if (document.forms[0].ShirtSize[i].checked)
{
alert('true');
}
else
{
alert('false');
}
}

Firefox will loop through once for each of the 3 buttons (in this case) and return false or true, consistent with what's been selected in the form. Safari returns false regardless of which is selected.