unicode with iFrame

[airplane_vn]

i'm seeking for a free WYSIWYG edior in javascript
i've found one that is "TextArea Rich 3.0"
it use an iFrame for displaying html

but when i want to display some Unicode character , things seem not working
can anybody show me some reason

Code :

my htmlfile is : temp.htm
charset=utf-8

my java code
iFrame.document.location.href="temp.htm"

this iFrame is put inside a page with charset=utf-8 too