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                        /JavaScript進階篇

求解為什么點=沒有反應

<!DOCTYPE html>
<html>
?<head>
? <title> 事件</title> ?
? <script type="text/javascript">
?? function count(){
??? var? lya1=document.getElementById("txt1").value;
???? var lya2=document.getElementById("txt2").value;
???? var wzei=document.getElementById("select").value;
???? var rintur="";
?? ?
??? switch(wzei)
??? {
????? case "+":
????? rintur= parseFloat(lya1)+ parseFloat(lya2);
?????? break;
????? case "-":
????? rintur= parseFloat(lya1)-parseFloat(lya2);
????? break;
????? case "*":
????? rintur = parseFloat(lya1)* parseFloat(lya2);
????? break;
???? default:
????? rintur = parseFloat(lay1)/ parseFloat(lya2);
????? break;
?? }
???? document.getElementById("fruit").value=rintur;
?? }
? </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>
</html>