error in execution jsp statements

i had written a simple jsp program
that will ask the user to type the firstname and when u clicks submit it will display the name and some information.
this program should not run if user does not type anything in the textfield because in the program
if(name != null) it should again ask to type but the program is running without typeanything also.
what could be the reason please tell me.
this is the program
<html>
<head>
<title> Processing get requests with the data</title>
</head>

<body>
<% // begin of scriptlet
String name= request.getParameter("firstName");
if(name != null) {
%> <%-- end scriptlet to insert fixed template data --%>
<h1>
<%= new java.util.Date() %>
Hello <%= name %>, <br/>
Welcome to JavaServerPages!
</h1>

<%
}
else {
%>
<form action = "Welcome.jsp" method = "get">
<p>Type Your first Name and press Submit </p>
<p><input type = "text" name="firstName" />
<input type = "submit" value="Submit" />
</p>
</form>
<%
}
%>
</body>
</html>

try to print out the String <%=name %> and i think ull see that if the user doesnt input anything the string is not null.
it is just empty! like this "" or " "
so check to see if it is null or empty.
this is just by guessing so i may be wrong .

ya i too guessed like that but it is not displaying even "" just nothing.
why it is not checking that

did u try to compare like this?
if(name.equals(""))
try and see if it works.