安道生網站技術練功房 - 分享經驗，累積智慧

This message was edited 1 time. Last update was at 2008-10-04 10:17:07

請教一下,text欄位若沒輸入值即顯示提醒視窗...
狀況1:沒輸入值,點圖片,正常
狀況2:沒輸入值,按Enter鍵,異常!!(為何提示視窗會彈出兩次?)

<%@ page contentType="text/html; charset=UTF-8" %>
<html>
<head>
</head>
<body>
<%
	String a = null;
	a = request.getParameter("keyword");
	out.println(a);
%>
<script language="javascript">
	function test() {
		if( document.formt.keyword.value == "" ) {
			alert("請輸入值");
			return false;
		} else {
			return true;
		}
	}
</script>
<form name="formt" method="POST" action="/member/test.jsp" onsubmit="return test()">
	輸入:<input name="keyword" size="20" value="" type="text" onkeypress="if ( event.keyCode == 13 ) test();">	
		 <a href="javascript:void(test())"><img src="/images/searchgame.gif" width="68" height="20" align="absmiddle"></a>
</form>
</body>
</html>

1.onkeypress會再按下Enter時執行一次test()，此外，按下Enter對瀏覽器而言等同於要求submit表單，於是表單被送出
2.onsubmit會在表單送出時執行一次test()

This message was edited 2 times. Last update was at 2008-10-04 11:48:34

andowson wrote:按下Enter對瀏覽器而言等同於要求submit表單，於是表單被送出

成功了,上面這句話點醒我.....謝謝指導!!

	輸入:<input name="keyword" size="20" value="" type="text" onkeyDown="if( event.keyCode == 13 && document.formt.keyword.value == '') { alert('請輸入值');return false;} else {return true;}">

安道生網站技術練功房 - 分享經驗，累積智慧

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