[Deff]

Hekumok,

<script type="text/javascript">
 var Arr_1 = [2, 'crack', 'find', 2];

 function Find_El_Array ( arr, val ) {
   var array_OUT = [];
   for(var i in arr) {if (val == arr[i]) array_OUT.push(i);}
   if(array_OUT.length) return array_OUT;
   return -1; 
 }

 alert( Find_El_Array (Arr_1, 2) )
 alert( Find_El_Array (Arr_1, 1) )

</script>