HTML_getValidSelected

Description: Checks for a valid selected value from a list of possible values. In case the value could not be found, a default value is taken.
Parameter:

• selected: Array or single value to check, if it is on the list of array keys.
• arrayKeys: An array that holds the possible returned values (array keys).
• defaultSelection: The value of the item to select by default.

Returns:

• A valid value from a list of possible values.