Notice: Undefined index: HTTP_X_REQUESTED_WITH in /home/b/balashgt/centreal.ru/public_html/site_dm/ajax/order_call.php on line 5
<pre>[RuntimeException] 
Could not start session because headers have already been sent. &quot;/home/b/balashgt/centreal.ru/public_html/site_dm/ajax/order_call.php&quot;:5. (0)
/home/b/balashgt/centreal.ru/public_html/bitrix/modules/main/lib/session/session.php:124
#0: Bitrix\Main\Session\Session-&gt;start()
	/home/b/balashgt/centreal.ru/public_html/bitrix/modules/main/lib/session/kernelsessionproxy.php:52
#1: Bitrix\Main\Session\KernelSessionProxy-&gt;start()
	/home/b/balashgt/centreal.ru/public_html/bitrix/modules/main/include.php:299
#2: require_once(string)
	/home/b/balashgt/centreal.ru/public_html/bitrix/modules/main/include/prolog_before.php:14
#3: require_once(string)
	/home/b/balashgt/centreal.ru/public_html/bitrix/modules/main/include/prolog.php:10
#4: require_once(string)
	/home/b/balashgt/centreal.ru/public_html/bitrix/header.php:1
#5: require(string)
	/home/b/balashgt/centreal.ru/public_html/site_dm/ajax/order_call.php:12
</pre>