checkedall checkboxen

HTML

<form>
  
<div id="cb"></div></form>
  <button id="reset" id="ww">
Boxen Reseten
  </button>
  <br><br>
  Shift gedrĂĽckt halten ,Boxen makieren ,und shift wieder los lassen"
  
 <br><br>
 Makierte Boxen ?
<div id="ausgabe">

</div>

JavaScript

for(i=1;i<=100;i++){
   var cbh = document.getElementById('cb');
    var cb = document.createElement('input');
    cb.type = 'checkbox';
    cb.name = 'box'+i;
    cb.value = i;
    cb.className = 'box';
    cb.id = 'box'+i;
    cbh.appendChild(cb);
}
var p=0;
function suche(){
   localStorage.setItem('k1',0);
   localStorage.setItem('k2',0);
   var elements = $("input.box:checked");
   $.each(elements, function(index, item) { 
       k=parseInt($(this).val());
       p++;
       if(p==1){
            localStorage.setItem('k1',k);
       }
       if(p==2){
            localStorage.setItem('k2',k);
       }
       for(t=localStorage.getItem('k1');t<=localStorage.getItem('k2');t++){
            $('#box'+t+'').attr("checked",true)
            document.getElementById('ausgabe').innerHTML+='<br>Id der Box = "Box'+t+'"';
        }
   });
}
 document.body.addEventListener ('keydown', function (event) {
 if (event.shiftKey==1){
       document.body.addEventListener ('keyup', function (event) {
       suche()
 });
 }else{
  }
});