I created this routine to deal with this situation and do cut/paste/modify from javascript to code
sub doPostBack
{
my $agent = shift; ## WWW::Mechanize agent-object passed in
my $target = shift; ## first argument in the __doPostBack() cal
+l in javascript
my $arg = shift; ## second argument in the __doPostBack() ca
+ll in javascript
# convert the passed in string
$target =~ s/\$/:/g;
$agent->form_number(1);
$agent->field('__EVENTTARGET', $target);
$agent->field('__EVENTARGUMENT', $arg);
$agent->submit();
} #endsub doPostBack
# function __doPostBack(eventTarget, eventArgument) {
# var theform;
# if (window.navigator.appName.toLowerCase().indexOf("microsoft") >
+ -1) {
# theform = document.MTMMAIN;
# }
# else {
# theform = document.forms["MTMMAIN"];
# }
# theform.__EVENTTARGET.value = eventTarget.split("$").join(":");
# theform.__EVENTARGUMENT.value = eventArgument;
# theform.submit();
# }