Radio Button

The Radio Button control lists one possible value for a set of mutually exclusive values that a user can choose from. You determine the list of possible values by creating multiple Radio button controls and giving them all the same Input attribute.

Example Radio Button control

The benefits of a Radio Button control are listed below.

• The user sees a complete list of values to choose from on the same form as the control.
• The user has a visual indicator for the currently selected value.
• You can control both the label users see for the option (the Caption attribute) and the actual value the option has when stored in the database (the Value attribute).

The costs of a Radio Button control are listed below.

• The more options there are to display, the more of the form's screen space is required to display them.
• You have to use a Frame or Group control to indicate that a list of Radio Button options are related.
• The list of values is only stored on the form and not in a global list or related record. This means you have to keep track of which forms use a particular list if you want to re-use the list in another form.
• The only way to change the list of values is to change the value of each individual Radio Button control.
• Each Radio Button option increases the size of the form. The larger a form is, the longer it takes for the client to initially display it.

A list of Radio Button options is very easy for your system to display since there are no link queries run or global lists to update at start-up. However, a list of Radio Button options requires more form space than using a single Combo box or Comfill control.

In general, a Radio Button control is best used in the following circumstances.

• There are few enough options to display that the user can see them all without needing to scroll to see more options.
• The list of options either does not change at all or changes infrequently.
• You want a visual indicator to highlight the currently selected value.
• You cannot select more than one value at a time with this control.

If you have more than a few options to display, consider using a Combo Box control instead to reduce the amount of screen space required to display the options. Also, if you expect to re-use the list of options in another form or in other circumstances, consider creating a global list so the options will be available for multiple forms. If you want users to be able to select more than one value from a list of values, consider creating a list of checkboxes.