console.log(zeroFill(11090, 8));
console.log(zeroFill(120, 2));
console.log(zeroFill(120, 5));

function zeroFill(num,val)
{
   var temp = num.toString().split('');
   var gen = val-(temp.length);
   var arr = [];
   if(val<=(temp.length))
   {
       return 'Invalid';
   }
   else
   {
    for(var i =0 ; i<gen ; i++)
      {
           arr[i] = '0';
      }
       var ar = (arr +','+ temp);
       return ar;
   }
}