Page Not Refreshing Properly

I am in the process of building a custom CMS in PHP, using TinyMCE as my Rich Text Editor. I had a odd problem where after saving my changes and being redirected back to my editor, my changes weren’t being refreshed. I had to shift + reload the page to see the new content. I tried everything I could think of with no success, when a user on the Freenode servers directed me to this code.

// Disable caching
function http_last_modified( $time = NULL )
{
	if ( $time === NULL ) $time = time();
	
	$new_last_modified = gmdate( 'D, d M Y H:i:s' , $time ) . ' GMT';
	if ( isset( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) 
	{
		$if_modified_since = preg_replace( '/;.*$/' , '' , $_SERVER['HTTP_IF_MODIFIED_SINCE'] ); 
		if ( $if_modified_since == $new_last_modified ) 
		{
			header( 'HTTP/1.0 304 Not Modified' );
			exit(0);
		}
	}
	header( "Last-Modified: $new_last_modified" );
}
http_last_modified();

It works like a charm!