use Tk;
use LWP::Simple;
use LWP::UserAgent;
use FileHandle;

$mw = MainWindow -> new;what
$screw = $mw -> Button ( -text => "screw up ticker file", 
   -command => [ \&alter_file ] ) -> pack;
$go = $mw -> Button ( -text => "go", 
   -command => [ \&process ] ) -> pack;
$stop = $mw -> Button ( -text > "stop", 
   -command => [ \&stop_process ] ) -> pack;

$html_source = new LWP::UserAgent;

MainLoop;


sub alter_file {
	open ( HANDLE1, "+< file" );  #  OPEN FOR READ/WRITE
	while ( <HANDLE1> ) {
		chop; chop; chop;  #  SCREW UP file
	}
	close HANDLE1;
}

sub process {
	open ( HANDLE2, "< file" );  #  OPEN FOR READ-ONLY

    #  WANT TO LOCK HANDLE2 SO THAT USER CAN'T SCREW UP file WHILE 
    #  THE FOLLOWING CODE EXECUTES

	while ( <HANDLE2> ) {
		$html_source -> get ( "http://quicktake.morningstar.com/
             FundNet/Snapshot.aspx?Symbol=$_" );
		#  DO WHATEVER WITH $html_source CONTENT
	}
	close HANDLE2;
}

sub stop_process {
	#  WANT TO SIGNAL USERAGENT $html_source TO STOP (OR DESTROY?) 
    #  ITSELF
	#  (AS A SIDE QUESTION: ASSUMING IT'S STILL OPEN, HOW WOULD I 
    #  THEN CLOSE HANDLE2?)
}