select option 추가 삭제 > JS

<script>

function removeOption(){
  var objSel = document.getElementById("wr_8");

  //alert(objSel.options[i].text +"//"+ objSel.options[i].value +"//"+ i);
  for(i=objSel.length; i>=0; i--){
    objSel.options[i]=null;
  }

}

function sel_change(val){
removeOption();

  var objSel = document.getElementById("wr_8");
  
         
    var objOption = document.createElement("option");   objOption.text ="전장선택"; objOption.value = "";   objSel.options.add(objOption);
     var objOption = document.createElement("option");  objOption.text ="S-CUT 10"; objOption.value = "S-CUT 10";   objSel.options.add(objOption);
     var objOption = document.createElement("option");  objOption.text ="S-CUT 15"; objOption.value = "S-CUT 15";   objSel.options.add(objOption);
     var objOption = document.createElement("option");  objOption.text ="S-CUT 35"; objOption.value = "S-CUT 35";   objSel.options.add(objOption);
    var objOption = document.createElement("option");   objOption.text ="S-CUT 50"; objOption.value = "S-CUT 50";   objSel.options.add(objOption);
 

  }

}

</script>