XmRepTypeValidValue tests the validity of a numerical
value for a given representation type resource. The function
generates a default warning message if the value is invalid
and the enable_default_warning argument is non-NULL.
rep_type_id
Specifies the identification number of the representation
type.
test_value
Specifies the numerical value to test.
enable_default_warning
Specifies the ID of the widget that contains a default warning
message. If this parameter is NULL,
no default warning message is generated and
the application must provide its own error handling.
Return value
Returns True if the specified value is valid; otherwise, returns False.