diff --git a/demo/demo.php b/demo/demo.php
index 37d1bde..f2e392f 100644
--- a/demo/demo.php
+++ b/demo/demo.php
@@ -1,36 +1,36 @@
 <?php
-	//display error in runtime
-	ini_set('display_errors','on');
-	error_reporting(E_ALL);
-	
+    //display error in runtime
+    ini_set('display_errors','on');
+    error_reporting(E_ALL);
+    
     require '../markdown.class.php';
-	
-	header("Content-type: text/html; charset=utf-8"); 
-	$obj 			= new Markdown();
+    
+    header("Content-type: text/html; charset=utf-8"); 
+    $obj             = new Markdown();
 
-	$mdFile 		= 'markdown_document.md';		//orig
-	$htmlFile		= 'markdown_html.html';
+    $mdFile         = 'markdown_document.md';        //orig
+    $htmlFile        = 'markdown_html.html';
 
-	$html2mdFile	= 'html_2_md.md';				//parse
-	$md2htmlFile	= 'md_2_html.html';
+    $html2mdFile    = 'html_2_md.md';                //parse
+    $md2htmlFile    = 'md_2_html.html';
 
-	$mdBackFile 	= 'markdown_back.md';			//parse and parse back
-	$htmlBackFile	= 'html_back.html';
+    $mdBackFile     = 'markdown_back.md';            //parse and parse back
+    $htmlBackFile    = 'html_back.html';
 
-	$md 			= file_get_contents($mdFile);
-	$md2html		= $obj->parseMarkdown($md);
-	file_put_contents($md2htmlFile, $md2html);		//md => html
+    $md             = file_get_contents($mdFile);
+    $md2html        = $obj->parseMarkdown($md);
+    file_put_contents($md2htmlFile, $md2html);        //md => html
 
-	$html 			= file_get_contents($htmlFile);
-	$html2md		= $obj->parseHtml($html);
-	file_put_contents($html2mdFile, $html2md);		//html => md
+    $html             = file_get_contents($htmlFile);
+    $html2md        = $obj->parseHtml($html);
+    file_put_contents($html2mdFile, $html2md);        //html => md
 
-	$mdBack			= $obj->parseHtml($md2html);
-	file_put_contents($mdBackFile, $mdBack);		//md => html => md
+    $mdBack            = $obj->parseHtml($md2html);
+    file_put_contents($mdBackFile, $mdBack);        //md => html => md
 
-	$htmlBack		= $obj->parseMarkdown($html2md);
-	file_put_contents($htmlBackFile, $htmlBack);	//html => md => html
-	
-	echo 'Done';
+    $htmlBack        = $obj->parseMarkdown($html2md);
+    file_put_contents($htmlBackFile, $htmlBack);    //html => md => html
+    
+    echo 'Done';
 
 //End_php
\ No newline at end of file