sub setExensionFilesChk{
	
	my $extensionNameIndex = $_[0] || return ;
	$extensionNameIndex = ($extensionNameIndex -1);
	my $extNameIs = "$extensionNames[$extensionNameIndex][0]";
	
	$extFileFrame->destroy if $extFileFrame;
	
	$extFileFrame = $fileListPane -> Frame();
	$extFileFrame->configure( -width=>575, -height=>400 );
	$extFileFrame -> grid(-row=>1,-column=>1,-columnspan=>4,-sticky=>"nw");
	
	my $rowIndex = 1; # start with 1 so that 'row' 0 is empty and resurved for the "total count label"
	my ($rdb1,$rdb2,$but,$lab);
	
	my @tmpFiles = getExtensionsFiles("$extNameIs");
	for my $names ( @tmpFiles ) {
		$rowIndex++;
		
		# add 'Delete' button...
		$but = $extFileFrame -> Button(-text=>"x", -command => [ \&setFileType_BothOrInstall_Or_Delete, "@$names[0]", 'delete', \$extensionNameIndex ]);
		$but -> grid(-row=>$rowIndex,-column=>0, -sticky=>"w");
		
		# Radio Buttons...
		$rdb1 = $extFileFrame -> Radiobutton(-text=>"Both", -value=>"both_@$names[0]", -variable=>"both_@$names[0]", -command => [ \&setFileType_BothOrInstall_Or_Delete, "@$names[0]", 'both' ]);
		$rdb1 -> grid(-row=>($rowIndex),-column=>1, -sticky=>"w");
		
		$rdb2 = $extFileFrame -> Radiobutton(-text=>"Install", -value=>"install_@$names[0]", -variable=>"both_@$names[0]", -command => [ \&setFileType_BothOrInstall_Or_Delete, "@$names[0]", 'install' ]);
		$rdb2 -> grid(-row=>($rowIndex),-column=>2, -sticky=>"w");
				
		if("@$names[1]" eq "both"){
			$rdb1 -> select();
			$rdb2 -> deselect();
		} else {
			$rdb1 -> deselect();
			$rdb2 -> select();
		}
		
		# label with file path and file name...
		$lab = $extFileFrame -> Label(-text=>" - @$names[2]@$names[3]");
		$lab -> grid(-row=>($rowIndex),-column=>3, -sticky=>"w");
		
	}
	@tmpFiles=();
	
	my $lbl_extCount = $extFileFrame -> Label(-text=>"($rowIndex) Extension Files:");
	$lbl_extCount -> grid(-row=>1,-column=>3,-columnspan=>1, -sticky=>"w");
	
	$extensionsFilesWindow->update;
	
}