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                        /JavaScript進階篇

沒反應為什么沒看出來錯那了

<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>??
??<script?type="text/javascript">
???function?count(){
????
????var?result="";
????//獲取第一個輸入框的值
????var?x?=?document.getElementById("txt1").value;
????//獲取第二個輸入框的值
????var?y?=?document.getElementById("txt2").value;
????//獲取選擇框的值
????var?dd?=?document.getElementById("select").value;
????
????//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(dd){
????????case?"+":
????????????result?=??parseInt(x)+parseInt(y);
????????????break;
????????case?"-":
????????????result?=??parseInt(x)-parseInt(y);
????????????break;
????????case?"*":
????????????result?=??parseInt(x)*parseInt(y);
????????????break;
????????case?"/":
????????????result?=??parseInt(x)/parseInt(y);
????????????break;
????}
????alert("ssss");
????
????//設置結果輸入框的值?
????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='?=?'?onclick="count()"?/>?<!--通過?=?按鈕來調用創(chuàng)建的函數，得到結果-->?
???<input?type='text'?id='fruit'?/>???
?</body>
</html>