#!/usr/bin/perl

use CGI qw(:standard);

print header,start_html('Sample CGI');

print "<font face = \"verdana\" size = 2 >";
if (param('dna')){

    &print_output();
}
else{
    &print_form();
}


print "</font>";    
print end_html;


sub print_form{
    print "<form action='http://biokdd.informatics.indiana.edu/cgi-bin/juhur/L519Lab/Lab2/sample2.cgi' method='POST'>";
    print "Hello!! Please enter the DNA sequence :<p>";
    print "<textarea  name='dna' rows=5 cols=50></textarea><br><br>";
    print "<input type='submit' name='submit'> ";
}


sub print_output{
 
    my $dna = param('dna');
    
    chomp $dna;
    
    if ($dna =~ /[^ACGTacgt]/){
	print "Sorry !! Your DNA sequence was not valid please enter a valid DNA sequence <p>";

    }
    else{
    
	print "Your input DNA sequence was <br> $dna <p>";

	$revcom = reverse $dna;
	
	$revcom =~ tr/ACGTacgt/TGCAtgca/;
	
# Print the reverse complement DNA onto the screen
	print "Here is the reverse complement DNA:<br>";
	
	print "$revcom<p>";
	

}
}