Getting selected text with codes

Hi,
I want to get the selected text within the editor with its code, i mean:
say, i have <strong>abba</strong>, meaning that bold "abba", i can only get, abba text, not the "<strong>abba</strong>"

i'm using this function to get the selected data,
function get_fck_selected(obj)
{
if (document.all)
{
return (FCKeditorAPI.GetInstance(obj).EditorDocument.selection.createRange().text);
}
else
{
return (oSel = FCKeditorAPI.GetInstance(obj).EditorWindow.getSelection());
}
} // function get_fck_selected(obj)

what should i change in this