The code looks ok to me.

 
>> it shows Arial if I click outside the box

It looks like the content you click is using the Arial font.

>>Times if I click inside the box

If you don't use Editor.EditorWysiwygModeCss Property to specify the location of the style sheet that will be used by the editable area.  By default, browser will use the Times by defaul. That's why the fontname dropdown shows the Times.

>>and no changes at all if I select text and change text !!!!!!!!!

Not sure what you mean. Can you create an example and show me the steps to reproduce the problems.