print "please enter the start point of your DNA sequence\n\n";
$dnastart = <STDIN>;
chomp $dnastart;
print "please enter the end point of your DNA sequence\n\n";
$dnaend = <STDIN>;
chomp $dnaend;

$dna = substr($dna, $dnastart, ($dnaend - $dnastart));

print"Here is your selected DNA sequence:\n\n $dna\n\n";
}


#start the string from position 0
$protein = substr($dna,0);
#Translate the DNA to protein
$protein = dna2peptide($protein);
#Print the sequence in lines of 50 characters long
print"\n\n<----------------Peptide frame 1----------------> \n\n";
print_sequence ($protein,50); 

# printing data sequences to HTML
print OUTFILE "<table border=1 width=50% bgcolor=#CCFFFF>
<tr><td><b>  Peptide sequence frame 1</td></tr></b>
<tr></tr>
<tr><td> $protein </td></tr>
</table>";