死活显示不了输出框的值，求解答！-慕课网

死活显示不了输出框的值，求解答！

来源：6-11 编程练习

Dorr

2017-01-23 18:14

<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
   function count(){
      var num1 = parsefloat(document.getElementById("txt1").value);
     var num2 = parsefloat(document.getElementById("txt2").value);
     var sel = document.getElementById("select").value;
var result ;
    switch(sel){
        case "+" :
               result = num1 + num2;
            break;
        case "-" ：
              result = num1 - num2;
           break;
        case "*" :
              result = num1 * num2;
            break;
            default :
             result = num1 / num2;
            ;
    }
    document.getElementById("fruit").value=result;

   }
</script>
</head>
<body>
   <input type='text' id='txt1' />
   <select id='select'>
  <option value='+'>+</option>
  <option value="-">-</option>
  <option value="*">*</option>
  <option value="/">/</option>
   </select>
   <input type='text' id='txt2' />
   <input type='button' value=' = ' onlick="count()" /> 
   <input type='text' id='fruit' />
</body>
</html>