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                        /JavaScript進(jìn)階篇

到底你哪錯(cuò)了啊????

<!DOCTYPE html>
<html>
?<head>
? <title> 事件</title> ?
? <script type="text/javascript">
?? function count(){
??? var tonum1=document.getElementById("txt1").value;
??? var tonum2=document.getElementById("txt2").value;
??? var toSelect=document.getElementById("select").value;
??? var toFruit="";
??? switch(toSelect){
??????? case "+":
??????? toFruit = parseFloat(tonum1) + parseFloat(tonum2);
??????? break;
??????? case "-":
??????? toFruit = parseFloat(tonum1) * parseFloat(tonum2);
??????? break;
??????? case "*":
??????? toFruit = parseFloat(tonum1) - parseFloat(tonum2);
??????? break;
??????? default:
??????? toFruit = parseFloat(tonum1) / parseFloat(tonum2);
??? }
??????? document.getElementById("fruit").value = toFruit;

?? }
? </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=' = ' oncilck='count()'/>
?? <input type='text' id='fruit' />? ?
?</body>
</html>