how JSP codes residing in js function works

Hi,

I would like to check with you how JSP codes residing in js function works.

How can I get the 2nd select stmt executed based on the values retrieve from 1st select statement and the conditions pass in to this js function

How can I get the select statement to execute only when a condition is met.

The following is the codes. It is not executing the 2nd select statement. when I didnt put in the 2nd select stmt, i manage to execute codes in that portion

script
====
function test(obj, obj2) {
<%
sql_query = "SELECT a1, a2 , a3, a4, a5 "+
" FROM table_a ";
try {
rset = db.execSQL(sql_query);
}
catch(SQLException e){
System.err.println ("Error in query " +e);
}
%>

var po_ln_fnd = false

<% while (rset.next()) {
j_a1 = rset.getString("a1");
j_a2 = rset.getString("a2");
j_a3 = rset.getString("a3");

%>

if ((eval(obj2.value)== '<%=j_a1%>')) {
if ((obj.value == '<%=j_a2%>') ) {
<% j_a4 = rset.getString("a4");
j_a5 = rset.getString("a5");

sql_query = "SELECT b2, b3, b4 "+
" FROM table_b "+
" WHERE b1 = '"+j_a3+"' ";
try {
rset = db.execSQL(sql_query);
}
catch (SQLException e) {
System.err.println("Error in query " +e);
}
while (rset.next()) {
j_b2 = rset.getString("j_b2");
j_b3 = rset.getString("j_b3");
j_b4 = rset.getString("j_b4");
}
%>
}
}
<%}>
}