jquery attr('checked','checked') works only once

I have a problem finding reason for the following jquery/checkbox behaviour. ``` $( this.obj + ' table.sgrid-content > thead > tr > th > input.select_all' ).on( 'click' , {grid:this} , function(event){ var grid = event.data.grid; if( $(this).is(':checked') ){ $( grid.obj + ' table.sgrid-content > tbody > tr > td > input.select ' ).attr('checked','checked'); $( grid.obj + ' .sgrid-content > tbody > tr > td > input.select ' ).parents('tr').addClass('ui-state-highlight'); } else { $( grid.obj + ' table.sgrid-content > tbody > tr > td > input.select ' ).removeAttr('checked'); $( grid.obj + ' table.sgrid-content > tbody > tr > td > input.select ' ).parents('tr').removeClass('ui-state-highlight'); } }); ``` The code is intended to work as follows: - click on input.select_all triggers the event - if input.select_all is checked: add attribute checked to all checkboxes marked as .select within table.sgrid-content - if not: remove the 'checked' attribute from all input.select items. Yet another simple grid function. And it works. The weird part is, it works only once. By that I mean, you can select all the checkboxes and deselect them. After that operation "Select all" function stops working. Another weird thing is, when i check dom elements with firebug they all become checked='checked' attr as they should, but they display and behave as they were not checked. Selectors work as they should. The code part with adding/removing ui-state-highlight works all the time. Word of explenation: grid - is the object that I pass to get grid.obj ( basically ID of a ceratain div ) Please give me your opinion.