<form action="loginCl.jsp" method = "post">
用户名：<input type = "text" name = "name" ><span style ="color:red">
<% request.getParameter("msg")!=null?request.getParameter("msg"); %></span><br>
//在“!=”上报错，信息为标记“!=”上具有语法错误，AssignmentOperator 无效
密码：<input type = "password" name = "pwd" /><br>
<input type = "submit" value = "提交" />
</form>
用户名：<input type = "text" name = "name" ><span style ="color:red">
<% request.getParameter("msg")!=null?request.getParameter("msg"); %></span><br>
//在“!=”上报错，信息为标记“!=”上具有语法错误，AssignmentOperator 无效
密码：<input type = "password" name = "pwd" /><br>
<input type = "submit" value = "提交" />
</form>
