computer.jsp

《JSP基础教程》

<%@ page contentType="text/html;charset=GB2312" %> 
<form action="" method=post name=form>
<input type="password" name="ok" >
<input type="submit" value="确定" name=sumbit>
</form>
<%
   String a=request.getParameter("ok");
   if(a==null)
     {
       a="1";
     }
    try
       {
        double num=Integer.parseInt(a);
        out.print("<br>"+Math.sqrt(num));
       }
    catch(NumberFormatException e)
       {
        out.print("<br>"+"请输入数字");
       }
%>