Problem with acrobat 9 when validating text fields

hello
i've been using script provide feedback english students. correct input turns backgroundcolor green, incorrect 1 turns red. script has been working fine many years including acrobat reader 8, version 9 gives me problem. when filling in field , pressing enter, nothing happens, when give focus filled in field again color change. leaving field turns color again original. here link example:
http://schulen.eduhi.at/herderschule/pdf/e3/e3u1sentences.pdf
try reader 9 , previous version , you'll see mean.
can me fix problem?

here code i'm using validate textfields:

//
//testletter
//
/*********** belongs to: document-level:testletter ***********/
     var f = this.getfield("1")
          f.value = "";
          
     var f = this.getfield("2")
          f.value = "";       
          
function testletter(fieldname,fieldvalue)
{
  var retvalue;
   retvalue = false;
  switch (fieldname)
  {
    case "1":
    {
      if (fieldvalue == "in australian bush.")
           retvalue = true;
         break;
}
    
    case "2":
    {
      if (fieldvalue == "for pack of dingoes.")
           retvalue = true;
       
             break;
       }
     default:
   {
     retvalue = false;
     break;
   }
}
  return  retvalue;
}

//
//

//
//trim
//
/*********** belongs to: document-level:trim ***********/
function trim(inputstring) {
  
   if (typeof inputstring != "string") { return inputstring; }
   var retvalue = inputstring;
   var ch = retvalue.substring(0, 1);
   while (ch == " ") {
      retvalue = retvalue.substring(1, retvalue.length);
      ch = retvalue.substring(0, 1);
   }
   ch = retvalue.substring(retvalue.length-1, retvalue.length);
   while (ch == " ") {
      retvalue = retvalue.substring(0, retvalue.length-1);
      ch = retvalue.substring(retvalue.length-1, retvalue.length);
   }
   while (retvalue.indexof("  ") != -1) {
      retvalue = retvalue.substring(0, retvalue.indexof("  "))
    + retvalue.substring(retvalue.indexof("  ")+1, retvalue.length);
   }
   return retvalue;
}
//
//

//
//1:validate
//
/*********** belongs to: acroform:1:validate ***********/
event.value = trim(event.value);
var f = this.getfield("1"); /* field event occurs @ */
     f.readonly = false;
     f.fillcolor = color.ltgray
if (event.value != "")
  if (testletter("1",event.value)==true)
  {
    f.fillcolor = color.green;
}
else
  {
  f.fillcolor = color.red;
}
//
//

//
//2:validate
//
/*********** belongs to: acroform:2:validate ***********/
event.value = trim(event.value);
var f = this.getfield("2"); /* field event occurs @ */
     f.readonly = false;
     f.fillcolor = color.ltgray
if (event.value != "")
  if (testletter("2",event.value)==true)
  {
    f.fillcolor = color.green;
}
else
{
f.fillcolor = color.red;
}
//
//

you have field highlighting turned on. can use javascript in file turn off user preference setting.

i'd suggest code change:

 
event.value = trim(event.value); 
var f = event.target; /* field event occurs @ */ 
... 
 

george

More discussions in Acrobat SDK

adobe