JSP and JavaScript! How to put session values into html form?

Question

I have a master form which goes to detail form to input data and back to master to Confirm submit operation. I want to put all the form data into request or session variable so it can be retrieved in both the forms. In master form i want to use it in the following way:
MasterForm-onLoad(){
check for form data Object in the session/request
if the data exists
populate the form fields (by getter methods of form data object)
Show the input from detail form
otherwise
show empty form
Now the problem is that it throws null pointer exception if the form data does not exist and i try to access it within an IF statement.
I beleive this is coz the JSP code will be executed on the server before the html page is loaded. Can any one please tell me how to solve this problem.
Thanks and Best Regards
Gul

Answer 1

thats exactly what i m doing but the session variable is not a simple variable or objct, its a serializable object with getters and setters which i will call to retrieve its values. its like this
FormBean formData=(FormBean) session.getAttribute("formData");
now in javaScript i will have to check if the formData is null and than perform the getters or setters.
<script>
function getValues(){
if("<%formData%>"!="null"){
form1.SID.value="<%=formData.getIDVal()%>"
</script>
thats what i was trying to do but the problem is all jsp code will be executed before the page is loaded so it will try to execute inside of the if statement even when the object is null so NullPointerException.
The only way i have got it working so far is to retrieve all the values in the JSP scriptlet, and than use the individual variables as u also mentioned.... SO Far i havnt been successful in calling getter methods in JavaScript. you think it can be done?
Thanks for the reply
GUL