im really a beginner, my knowledge comes from youtube videos :D. I really dont know how to continue... if anybody has an idea please let me know!

for (var i = 0; i < ing.length; i++) {
  for (var ii = 1; ii < ing[i].length; ii++) {
    var div   = document.createElement('DIV');
    var slide = document.createElement("INPUT");
    slide.setAttribute("type", "range");
    slide.setAttribute("id", "slide_" + i + "_" + ii);
    slide.setAttribute("value", 0);

    var slide_value = document.createElement("span");
    slide_value.setAttribute("id", "slide_value_" + i + "_" + ii);
    slide_value.innerText = 0;
    var text = document.createTextNode(" %");

    slide.oninput = function() {
      /*
      *
      *
      from here it doesn't work:
      Error message: Uncaught TypeError: slide_value is null
      I don't understand this, wasn't it assigned a value?
      *
      *
      */

      //with:
      console.log(i, ii);
      /*
      i only get the last values for both, i and ii; 
      doesnt matter which slide i pull. any ideas? 
      May there is the problem..
      */

      slide_value.innerText = this.value;
    }

    div.append(slide_value, text, slide);
  }
}

regards Luca