Post XML dato With ASIFormDataRequest error

[ufsirfi]

\[quote\]\[code\]NSURL *postUrl =[[NSURL alloc] initWithString:mainString];\[/code\]\[/quote\]\[code\]ASIFormDataRequest *request = [ASIFormDataRequest requestWithURLostUrl];[request setResponseEncoding:NSUTF8StringEncoding];NSString *msgLength = [NSString stringWithFormat"%d", [xmlString length]];[request addRequestHeader"Content-Length" value:msgLength];NSString *contentType = [NSString stringWithFormat"application/xml"];[request addRequestHeader"Content-Type" value:contentType];\[/code\]// [request addRequestHeader"Content-Type" value"application/json"];//Test For JSON is good [request appendPostData:theData]; [request buildPostBody]; [request setRequestMethod"POST"];\[code\][request setDelegate:self];[request startAsynchronous];[request setTimeOutSeconds:20];//