PHP变量从一个php文件到另一个使用xmlhttp.open（）

is it possible to get the variable from first php file to second php file by calling the second php file using xmlhttp.open()?

First File:

$conn = sqlsrv_connect( $serverName, $connectionInfo);

Second File:

$result_slots = sqlsrv_query($conn, $query_slots);

I'm getting a Undefined error on the second file on $conn variable.