convert text box string into integer

i have an html file in which i m using a text box , for entering amount i m using that text box entry at next jsp. i want to convert amount string into integer for further processing. At next jsp i m using:-

String amount= request.getParameter("bal");

int ammount1= Integer.parseInt(ammount);

and in sql query i m using amount1 as:-

ResultSet rs1 = st.executeQuery("update saving set balance = balance - amount1 where saving.account_no = '" + acc +"'");

my problem is i m getting following error:-

server encountered an internal error and

exception:- numberformat exception

please help me as soon as possible

[665 byte] By [ama.banka] at [2007-11-27 0:28:13]