Use a parameter value in F4 help / Implement a wildcard F4 help

Question

Hi,
I would like to implement a F4 help for a parameter. The user should be able to enter a text to the parameter field hit F4 and get and help screen related to the text he just entered. (pretty much like the F4 help for SE16 or SE83)
My problem is, that the entered text is not available in the report.
REPORT SELECTION_SCREEN_F4_DEMO.
PARAMETERS: filename TYPE localfile LOWER CASE.
AT SELECTION-SCREEN ON VALUE-REQUEST FOR filename.
  CALL SCREEN 100 STARTING AT 10 5
                  ENDING   AT 50 10.
MODULE VALUE_LIST OUTPUT.
  SUPPRESS DIALOG.
  LEAVE TO LIST-PROCESSING AND RETURN TO SCREEN 0.
  SET PF-STATUS SPACE.
  NEW-PAGE NO-TITLE.
  WRITE: 'Pattern:', filename COLOR COL_HEADING.
* selection of filenames ...
  CLEAR filename.
ENDMODULE.
AT LINE-SELECTION.
  CHECK NOT filename IS INITIAL.
  LEAVE TO SCREEN 0.
If a value was entered at the selection screen and a break point is set in MODULE VALUE_LIST OUTPUT, value filename is always empty.
How can the current value of parameter filename be accessed in the program?
Thanks in advance
Dominik

Answer 1

You would have to use a form, with hidden parameters and a method="post". Your Next link could be a submit button, or be a link with an onclick event that submitted the form:
<c:url var="thisURL" value="homer.jsp"/>
<form name="iqform" action="<c:out value="${thisURL}"/>">
  <input type="hidden" name="iq" value="<c:out value="${homer.iq}"/>"/>
  <input type="hidden" name="checkAgainst" value="marge simpson"/>
  <input type="submit" value="Next"/>
  <!-- or -->
  <script type="text/javascript">
    function submitIqForm() {
      document.iqform.submit();
  </script>
  <a href="javascript: submitIqForm()">Next</a>
</form>