Auto Incrementing HTML Form ID's in input field

Question

How does one auto-increment Id's to an HTML form so it's easier to classify? Kind of like an invoice/reference number? In other words, is it possible to create an hidden input field that would attribute a serie of numbers and also an ID automatically when the form page is loaded just like in Mysql for instance? The idea here is to make that happen for a form.

Answer 1

Im not familiar with JSP but im sure you can read and write files in JSP as this page says

JSP Reading Text File.

<%
String fileName = "/WEB-INF/NextID.txt";
InputStream ins = application.getResourceAsStream(fileName);
try
{
    if(ins == null)
    {
        response.setStatus(response.SC_NOT_FOUND);
    }
    else
    {
        BufferedReader br = new BufferedReader((new InputStreamReader(ins)));
        String data;

        int nextID = Integer.parseInt(data= br.readLine());

        %>
        <form name="myWebForm" action="mailto:[email protected]" method="post">
            First: <input title="Please Enter Your First Name" id="first" name="first" type="text" size="12" maxlength="12" /> 
            Last: <input title="Please Enter Your Last Name" id="last" name="last" type="text" size="18" maxlength="24" /><br />
            Password: <input type="password" title="Please Enter Your Password" size="8" maxlength="8" /><br /><br />

            <!--This the line you are asking for-->
            <input type="hidden" name="referenceNumber" id="referenceNumber" value="<%=request.getParameter("firstinput")%>" /><br />

            <input type="submit" value="SUBMIT" />
            <input type="reset" value="RESET" />
        </form>

        <%
    } 
}
catch(IOException e)
{
    out.println(e.getMessage());
}
%>

EDIT: Possible solution. I may have made some syntax error as i dont know JSP at all. Learnt by myself just now