$(document).ready(function(){
    
    $("#frequency").change(function() {
	if ( $("#frequency").val() != 'D' ) {
		$("#cmd").attr("value", "_xclick-subscriptions");
		$("#amount").attr("name", "a3");
	} else if ( $("#frequency").val() == 'D' ) {
		$("#cmd").attr("value", "_donations");
		$("#amount").attr("name", "amount");		
	}
});

  });