Problem with webbrowser document click and double click event for some html files.

Hi,
 
I am using webbrowser control to bind the html & text files data.
In that i want 2 options like Document click and Double click event.
In CLick event I want to retrieve the click position "word", and in the double click event I want to retrieve the "Sentance".
 
This is working fine for some files but some file it is not working properlly.

Please find the attachment code.