                        課程
                    
                        /前端開發
                        
                            /JavaScript
                        
                        /JavaScript進階篇

為什么輸不出結果??！

<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>??
??<script?type="text/javascript">
???function?count(){
????var?otxt1=document.getElementById("txt1").value;
????var?otxt2=document.getElementById("txt2").value;
????var?oselect=document.getElementById("select").value;
????var?result="";
????switch(oselect){
????????case"+":
????????????result=parseInt(otxt1)+parseInt(otxt2);
????????????break;
????????case"-":
????????????result=parseInt(otxt1)-parseInt(otxt2);
????????????break;
????????case"*":
????????????result=parseInt(otxt1)*parseInt(otxt2);
????????????break;
????????case"/":
????????????result=parseInt(otxt1)/parseInt(otxt2);
????????????
????}
???????document.getElementById("fruit")=result;
???????alert("ceshi");
???}
??</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='?=?'?onclick=count()?/>?<!--通過?=?按鈕來調用創建的函數，得到結果-->?
???<input?type='text'?id='fruit'?/>???
?</body>
</html>

好煩。。又不能想匯編語言那樣編譯會報錯。。找錯誤好難。。。