Dispaly the combobox selected value of servlet program in same page

[shrutinr]

Hi..
I m haiving problem in retrieving selected data from combobox of servlet page .
I have combobox in servlet and want to display selected value in d same page..
please help me to resolve this problem..
Here is my code:

PrintWriter pw=response.getWriter();
pw.write("<h1>Welcome to Shopping cart</h1>");
pw.write("<form name=myform method=post>");

HashMap<String, Integer> add= new HashMap<String,Integer>();
add.put("c",100);
add.put("C++",300);
add.put("Java",600);
Collection c=add.values();
Set s=add.keySet();
Iterator i=s.iterator();
pw.write("Product List<select name=list ><option>Select Books</option>");

Iterator<String> ie=s.iterator();
while(ie.hasNext())
{
pw.write("<option>" );
pw.write(ie.next());
pw.write("</option>");

}