select.js

  function getRangePos(obj){
    var Pos = 0; //ie
    if (document.selection){
      obj.focus();
      var Sel = document.selection.createRange();
      Sel.moveStart('character', -obj.value.length);
      Pos = Sel.text.length;
    }else if (obj.selectionStart || obj.selectionStart == '0'){
      Pos = obj.selectionStart;
    }
    
    return Pos;
  }
  
  function setRangePos(obj, pos){
    if (obj.setSelectionRange){
      obj.focus();
      obj.setSelectionRange(pos,pos);
    }else if (obj.createTextRange){
      var range = obj.createTextRange();
      range.collapse(true);
      range.moveEnd('character', pos);
      range.moveStart('character', pos);
      range.select();
    }
  }
  
  function get_click(){
    var obj = document.getElementById('soruce_id');
    var pos = getRangePos(obj);
    document.getElementById('info').innerHTML = document.getElementById('info').innerHTML  + 'Pos:' + pos +  '\n';
    obj.focus();
  }
  
  function set_click(){
    var obj = document.getElementById('soruce_id');
    var num = document.getElementById('pos_num');
    var numVal = parseInt(num.value);
    num.value = numVal;
    if (numVal > 0){
      setRangePos(obj, numVal);
    }
    obj.focus();
  }