blank lines at the top of source code page
<p>I am running into a weird issue, a php file which return a valid JSON except that it output a ton of blank lines at the very top of the file, so if the real output contains 300 lines of code, what I get is 300 + 500 blank lines at the beginning.</p>

<p>Please not that these blank lines are visible only when I show the source code of the page in my browser. How to get rid of that? </p>
