<html xmlns="http://www.w3.org/1999/xhtml&...<head runat="server"><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>提交</title></head><body><form id="form1" runat="server" action="WebForm25.aspx" onsubmit="return form1Submit();">
<div>
<label>
姓名： <input id="nameInput" type="text" />
</label>
<input type="submit" value="提交" />
</div></form><script type="text/javascript">
function form1Sumbit() { var nameInput = document.getElementById("nameInput"); if (nameInput.value == "") {
alert("【請輸入姓名】！");
nameInput.focus(); return false;
}
}</script></body></html>為啥不出彈框呢？求解
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