I am unable to find a VBScript example of how to disable an HTML form field. Below is is a line of code I've tried to translate from JavaScript. It doesn't seem to generate any errors but neither does it disable the radio buttons associated with the field name. What is wrong with it?

frmSurvey.fldAnswer5.Disabled=false

fldAnswer5 is the NAME attribute on two radio buttons. Neither button is disabled when this script is executed.