I want to write a javascript program which will change the font/color of the user selcted text on a web page.
Is it possible to know the exact location of the selected text from the web page.
I want a user to select a text on a web page and then my javascrip code should locate this text in the web page's source file.
I dont want to search for this text in the source file of the web page.
please help!!!!

I am working on javascript wherein i am trying to highlight the
selected text by changing its background color.

What I want exactly is:
1) When a page is loaded, the user will select some text on the page by
clicking and draggin the mouse
2) I am able to extract the selected text as a string
3) I want to access the exact position of the selected text in the
document object I am using in javascript

Can you please tell me how to access the exact position of text at some
position in the HTML page using the document object, since the same
text string can appear multiple times in the HTML page.