The following is for a complicated application I'm writing. I don't expect the first question can be answered, but why not try:

1) Suppose I have an element such as ARTICLE with an id such as "myArticle".  If the user clicks his mouse inside that element, I can find the position of the mouse (using .offset or something like that), but is there a way to find the text offset?  I don't see how there could be, unless the text letters were all the same width, (as in Courier font) and only if I knew there were no intervening images or paragraphs etc.  But I want to standardize it to the extent that if different users click on the letter A in APPLE, that even though their cursor position may vary by a few pixels when they click, I can return a standard number for the position.

2)

Also, I saw a JavaScript construct that I don't understand:

CurrentSelection.Selector.getSelected = function()

and

CurrentSelection.Selector.mouseup =  function()

It seems that these routines can get the exact text that is highlighted in a div, and then modify it.  Is there anything like that in jQuery?  Suppose  user moves his mouse over a word, and I want the word to change into an image of Count Dracula.  (I don't, but that's an example).  I know jQuery has $(#ELEMENT).HTML()  which could do that, but that usually depends on having an element.   I'm seeing JavaScript where you don't need to replace the entire element, just a part of it.  (The javascript code that I saw was at: http://jsfiddle.net/dipaks2011/uz0gsu8a/1/ )

Thanks.