Problem with ajax php call

I start a php call with callback function.

    r$ = "synccheckversion.php/?FileToGet=" & email$ & "&time=" & SysInfo(10)
    reqsync = Ajax(r$ ,"","", syncCheckVersion2 )

in the callback function I check reqsync

  If reqsync <> null Then

But reqsync is allways undefined. The script is on the server and if I try it manually in chrome browser on the pc it works, but from the app reqsync is always undefined.

Can you put some tracing on the PHP side?

I can do this and when I start the php in the chrome browser( with the complete server path) I see the results. But starting the app in the debugger from chrome browser I can see nothing because there is no return from the ajax call. The debugger jumps into the callback function but reqsync is null.

You can also use the Network tab in the Chrome Dev Tools to see what might be going on.