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                        /JavaScript進(jìn)階篇

實(shí)現(xiàn)不了到底哪錯(cuò)了呢？

<!DOCTYPE html>
<html>
?<head>
? <title> 事件</title>?
? <script type="text/javascript">
?? function count(){
??? var txt1 = document.getElementById("txt1").value;
??? var txt2 = document.getElementById("txt2").value;
??? var c= document.getElementById("select").value;
??? var result = "";
??? switch(c) {
??????? case "+":
??????????? result = parseInt(txt1) + parseInt(txt2);
??????????? break;
??????? case "-":
??????????? result = parseInt(txt1) - parseInt(txt2);
??????????? break;
??????? case "*":
??????????? result = parseInt(txt1) * parseInt(txt2);
??????????? break;
??????? default:
??????????? result = parseInt(txt1) / parseInt(txt2);
??? }
??? 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();' />
?? <input type='text' id='fruit'/>??
?</body>