text: function write7(){
      document.getElementById("panel").value += 7;
    }
  function clear1(){
      document.getElementById("panel").value = null;
    }
  function writed(){
      document.getElementById("panel").value += "/";
  }
  function backspace(){
      var x = document.getElementById("panel").value;
      document.getElementById("panel").value=x.substring(0,x.length-1);
  }
  function writem(){
      document.getElementById("panel").value += "*";
  }
  function writes(){
      document.getElementById("panel").value+="-";
  }
  function write8(){
      document.getElementById("panel").value += 8;
  }
  function write9(){
      document.getElementById("panel").value += 9;
  }
  function writep(){
      document.getElementById("panel").value += "+";
  }
  function write4(){
      document.getElementById("panel").value += 4;
  }
  function write5(){
      document.getElementById("panel").value += 5;
  }
  function write6(){
      document.getElementById("panel").value += 6;
  }
  function write1(){
      document.getElementById("panel").value += 1;
  }
  function write2(){
      document.getElementById("panel").value += 2;
  }
  function write3(){
      document.getElementById("panel").value += 3;
  }
  function write0(){
      document.getElementById("panel").value += 0;
  }
  function write00(){
      document.getElementById("panel").value += "00";
  }
  function writepoint(){
      document.getElementById("panel").value += ".";
  }
  function sub(){
      var x = (document.getElementById("panel").value);
      var F = (new Function ("document.getElementById('panel').value = "+x)());
      
  
  }
  
  
  
  
  
  