In ios platform SOAP API call gives error Response with status: 0 for URL: null

in ios platform i call sop web services but it gives error like Response with status: 0 for URL: null

anyone know how to fix this ??
this is my code :
var soapRequest =
’<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi=“

’ + this.MobileNo + ’
’ + this.Password + ’

var headers = new Headers();
headers.append(‘Content-Type’, ‘text/xml’);
headers.append(‘Access-Control-Allow-Method’, ‘POST’);
headers.append(‘Access-Control-Allow-Headers’, ‘X-Custom-Header’);
headers.append(‘Access-Control-Allow-Origin’, ‘’); + ‘UserLogin’, soapRequest, { headers: headers })