var numfiles=0;
function createNewFileInputs(){
	if ($('input:file[value=""]').length <1){
		numfiles++;
		$('<br/><input name="tkt_file'+numfiles+'" id="tkt_file'+numfiles+'" size="40" type="file">')
			.change(createNewFileInputs).click(createNewFileInputs)
			.appendTo('#file_row');
	}	
}

$().ready(function(){
	$('input:file').change(createNewFileInputs).click(createNewFileInputs);
});