SAPUI5 : How to set the date value format for DateTimeInput?

Hi SAPUI5 experts:

I'd like ask 2 things regarding the control: sap.m.DateTimeInput

1: Here is I want to do: show the current date (May 1, 2014) in the control in format as "01-05-2014". But by default the following code shows "May 1 2014". How can I show it as "01-05-2014"?

var oDateTimeInput = new sap.m.DateTimeInput({});

oDateTimeInput.setDateValue(new Date());                   //shown as "May 1 2014"

2. Can someone explain what difference is between the following settings of DateTimeInput?

   ValueFormat

   DisplayFormat

Please write a short code example.

Thanks very much in advance!

Br,

Dong