while(<INFILE>){
   
    #print "here\n";
    
    if ($_ =~ /^(.{1,50})\t{0,50}(.{0,50})\t{0,1}(.{0,50})\t{0,1}(.{0,50})\t{0,1}(.{0,50})\t{0,1}(.{0,50})\t{0,1}(.{0,50})\t{0,1}(.{0,50})\t{0,1}(.{0,50})/){
	
	#print "here_B\n";
	
	$bumb = "";

	$gene_id = $1;
	if ($2 =~ /.{1,50}/){ push (@alternative_ids, $2)}
	else{
	   push (@alternative_ids, $bumb); 
	}
	
	if ($3 =~ /.{1,50}/){ push (@alternative_ids, $3)}
	else{
	    push (@alternative_ids, $bumb);
	}
	
	if ($4 =~ /.{1,50}/){ push (@alternative_ids, $4)}
	else{
	    push (@alternative_ids, $bumb);
	}
	
	if ($5 =~ /.{1,50}/){ push (@alternative_ids, $5)}
	else{
	    push (@alternative_ids, $bumb);
	}
	
	if ($6 =~ /.{1,50}/){ push (@alternative_ids, $6)}
	else{
	    push (@alternative_ids, $bumb);
	}

	if ($7 =~ /.{1,50}/){ push (@alternative_ids, $7)}
	else{
	    push (@alternative_ids, $bumb);
	}
	
	if ($8 =~ /.{1,50}/){ push (@alternative_ids, $8)}
       	else{
	    push (@alternative_ids, $bumb);
	}
	
	if ($9 =~ /.{1,50}/){ push (@alternative_ids, $9)}
	else{
	    push (@alternative_ids, $bumb);
	}




	print @alternative_id; 

	foreach (@alternative_ids){
	    
	    $old_line = $new_line;
	    $alternative_id = $_;
	    
	    $new_line = "$gene_id\t$alternative_id\n"; 
	    
	    @record_previous_lines = qw/blank/;

		if ($new_line ne $old_line){ #discount consecutive repeats of identical lines
		    $switch = 1;

		foreach(@record_previous_lines){
		  
		    if ($_ =~ /$new_line.$old_line/){
			$switch = 2;
		    }
		}
		
		if ($switch = 1){ # don't print lines that have previously been repeated
		    print OUT_B "$new_line$old_line";
		}
		
		if (@record_previous_lines > 200){ # don't let this array get bigger than 200
		    shift @record_previous_lines; # shift deletes the first value of an array
		}
		push (@record_previous_lines, $new_line.$old_lines);
	    }
	}
	undef @alternative_ids;
    }
}