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                        /JavaScript進階篇

求大神看看哪里錯了

??<script?type="text/javascript">
???function?count(){
???????
???var?t1=document.getElementById("text1").value;//獲取第一個輸入框的值
???var?t2=document.getElementById("text2").value;//獲取第二個輸入框的值
???var?t3=document.getElementById("select").value;//獲取選擇框的值
???var?sum="";?????????????????//獲取通過下拉框來選擇的值來改變加減乘除的運算法則
????
???????switch(t3)
?????{case?"+":?sum=parseInt(t1)+parseInt(t2);break;
?????case?"-":?sum=parseInt(t1)-parseInt(t2);break;
?????case?"*":?sum=parseInt(t1)*parseInt(t2);break;
?????case?"/":?sum=parseInt(t1)/parseInt(t2);break;}
??
????document.getElementById("fruit").value=sum;//設置結果輸入框的值?
????
???}

??</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'/>