javascript - Expand right floated div to push left div -

so, have

<div style="width:250px;border: 1px solid;overflow:auto" id="container">     <div style="float:left;">vasileostrovsky rayon</div>     <div id="rightaligneddiv"> div expanding </div> </div> 

how can make #rightaligneddiv expand on left one. in other words when #rightaligneddiv wide enough, want push left 1 smaller, , left div can move new line :).

here fiddle demonstrate predicament http://jsfiddle.net/ec9zx/1/

this has solved somehow using css. js solution complicate logic much. , wouldn't elegant one.

window.alterwidth = function() {     var testwidth=parseint(document.getelementbyid("testid").style.width);     var testwidth1=parseint(document.getelementbyid("rightdiv").style.width);       document.getelementbyid("testid").style.width = (testwidth-33)+'px';     document.getelementbyid("rightdiv").style.width = (testwidth1+33)+'px';     var newimg = $('#com_ibm_ioc_spb_kpi_statusbox_412').clone();      $('#rightdiv').append(newimg);   } 

give id both div , make overflow auto first div.

also try fiddle http://jsfiddle.net/l774v/