I have a Servlet which will get parameters & values from another Servlet,
before processing it i need to manipulate the values,

fox example if user enters only the last 6 digits of a code and then i need to
prefix the first 6digits..
problem is, im already used the same field n number of times in caller Servlet

so i tried "HttpServletRequest.getParameterNames()"

im able retrieve the value of all parameters but i am not able to modify the
value of an parameter permanently..

so is there any method to change the value of parameters???
otherwise i have only one way, i.e., i need to validate using JavaScript