Hi,
You can make fields mandatory or optional with JavaScript code like this in the change event of the radiobuttonlist (the container of your Yes/No radio buttons). By default the first radio button will have a value of 1.
if (this.rawValue == 1)
{
CheckBox1.validate.nullTest = "error";
NumericField1.validate.nullTest = "error";
}
else
{
CheckBox1.validate.nullTest = "disabled";
NumericField1.validate.nullTest = "disabled";
}