Get the line number of selected text

Hi All,

Please tell me how to get the line number of the selected text in a page.

for example

Consider, below is the page with some text, in that i want to get the line number of that selected(marked in red) text

|-------------------------|

|xxxxxxxxxxxxxx|

|xxxxxxxxxx       |
|xxxxxxxxxxxxxx|

|xxxxxxxxxxxxxx|

|xxxxxxxxxx       |

|xxxxxxxxxxxxxx|

|xxxxxxxxxxxxxx|

---------------------------

Thanks in Advance

Shiv