javascript - Select Multiple Checkboxes By Cntrl + Click -

i have form has many checkbox elements lined in rows. implement function allows user hold cntrl, select checkbox , have every box either:

a) become checked there no initial box checked
b) become checked closest checked box

is possible? many thanks.

this .

the code shift+key

// usage: $form.find('input[type="checkbox"]').shiftselectable(); // replace input[type="checkbox"] selector match list of checkboxes  $.fn.shiftselectable = function() { var lastchecked,     $boxes = this;  $boxes.click(function(evt) {     if(!lastchecked) {         lastchecked = this;         return;     }      if(evt.shiftkey) {         var start = $boxes.index(this),             end = $boxes.index(lastchecked);         $boxes.slice(math.min(start, end), math.max(start, end) + 1)             .attr('checked', lastchecked.checked)             .trigger('change');     }      lastchecked = this; }); 

};

credits : jquery plugin shift + click select multiple checkboxes