jquery - Finding the number of sentences or lines in a paragraph in order to re-size its borders? -

i having trouble jquery function have created news page. able find number of rows/lines/sentences in amount of text ( few paragraphs
break lines in between them). reason need able re-size text area's borders allow rest of text read. user presented summary paragraph of size , if read more click button , text area opens reveal rest of text. need number of rows multiply font-size can fit of text new text-area, how can find number(the number of rows/lines in paragraph)?

code @ : http://jsfiddle.net/3nmhu/1/ or below -click 'v' bottom-right of text expand text area. -click 'a' bottom-right of text contract text area.

jquery:

$(document).ready(function(){     $('.read_less').hide();     $('.read_more').click(function(){        //confirm($(this).parent().text().length/12);        $('.news_item').fadeout('slow');     $(this).parents().fadein('slow');     $(this).hide();      $('.read_less').show('slow');     $(this).parent().animate({height:($(this).parent().text().length/50) *20 + 'px',width:'655px'},'slow');     //$('.bars2').show('slow');     //$('.bars').animate({width:'255px'},'slow');     //$('.bars2').animate({width:'255px'},'slow');       });     $('.read_less').click(function(){     $(this).parent().animate({height:'110px',width:'464px'},'slow');     $('.news_item').fadein('slow');     $('.read_less').hide();      $('.read_more').show();      }); }); 

i want create these news items each able define it's own expansion space allows text read , text fit in text area snugly , solution needs number of lines.however unsure how find number. moreover, if have better suggestion how remedy error , me solve task @ hand appreciated.

thanks in advance!

one approach take out div's offsetheight , divide it's line-height. give number of lines.

or can use getclientrects() function of javascript, think surely exact thing. function converts every line rectangle can length , number of lines.