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Some sample radio button form elements:

" method="get"> A Default No-Frills Radio Button:
Radio Button With An Associated Value:
Multiple Radio Buttons With The Same Name:
Radio Button Which Maintains Its State: />




Let's check out our values just submitted:

FYI: Note that the above form submits back to this same page. If you haven't yet submit the form then there won't be any values in the text below since they are retrieved from the form. In this case, the values reflected are simply the defaults and are the same results you would get if you submitted the form without checking anything.

The Default No-Frills Radio Button

By default, an HTML radio button element returns nothing if it wasn't enabled and a value of "on" if it was. So by checking its value we can determine if it was enabled or not when the form was submitted. The No-Frills Radio Button was: <% ' Note that "on" is in lower case. Since writing "on" ' doesn't do much good, I simply check for it to determine ' which branch of the conditional to execute. I could ' place whatever code I wanted inside either condition. ' In this case I simply print out a "user-friendly" message. If Request.QueryString("default") = "on" Then Response.Write "Enabled" Else Response.Write "Disabled" End If %> .

Radio Button With An Associated Value

If you don't like the fact that the radio button returns the value of "on" it's really easy to change. Simply add a value parameter and assign to it what you'd like the value returned by the radio button to be. The Radio Button With An Associated Value returned: <%= Request.QueryString("value_specified") %>.

Multiple Radio Buttons With The Same Name

Similarly to the checkbox, the scenario where you have a set of radio buttons all with the same name is probably one of the most useful ways to use this type of input tag. The main difference is that instead of allowing a user to specify multiple answers to one question, the radio button element ensures that one and only one selection is choosen from among the group of buttons that share a common name. Multiple Radio Buttons With The Same Name ensured that only one choice was selected and it was: <%= Request.QueryString("multiple") %>.

Radio Button Which Maintains Its State

At this point there's really nothing different about this radio button from any other, but I thought I should illustrate the technique when building the form (see the form generating section of the source code) because it's so useful in real life. In particular, when you're sending a user back to the form to check their entries, it's really frustrating for them if they have to re-enter all their values and re-select all the appropriate radio buttons.

In terms of the value, like I said, this is just like the standard radio button, but just to keep up the pattern... Radio Button Which Maintains Its State returned: <%= Request.QueryString("state_keeper") %>.

<% ' Here's a little function that you might find handy. ' It takes the name parameter of the radio button you want ' to check and will return a boolean indicating if a ' radio button with that name was enabled on the form when ' the user submitted it even if the value of the ' radio button isn't set to anything. It works well to ' help simplify your code... especially in conditionals. Function IsChecked(strFieldName) Dim blnChecked If Request.QueryString(strFieldName).Count > 0 Then blnChecked = True Else blnChecked = False End If IsChecked = blnChecked End Function ' For example, using the state_keeper example above: 'If IsChecked("state_keeper") Then ' ' The radio button was enabled. 'End If %>