I've checked it many times and there is not even 1 space or tab. I'm not sure but after i followed the link given by corbin, they tell me that the trouble may lays on the text editor. I usually used Notepad++, but i've created the page1.php using TextPad and just for fun i made the second used notepad++. After that i copy the content of page2.php to new document i created in textpad and save it there but in different document.
So my deduction is there is error in Notepad++, when it create a new document, just maybe, it's automatically add an invisible character at the beginning of document.