How can i create a popup(alert) message when a user enters a correct value or an incorrect value by clicking on the "Go" button . i am not sure how to connect the "Go" button with the java code .
please help
<%@ page import="java.io.*,java.util.*" %>
<html>
<body>
<%
int a =6;
int b = 8;
%>
<FORM METHOD=POST ACTION="main.jsp">
<%=a%>+<%=b%> = <INPUT TYPE=TEXT NAME=num SIZE=20>
<P><INPUT TYPE=SUBMIT value="Go"></p>
<P><INPUT TYPE=SUBMIT value="Continue" disabled="disabled" ></p>
</body>
</html>