Callout

public static void callOut(List<String> ids){

    	InvoiceAttachmentConnector.InvoiceAttachmentService ws = new InvoiceAttachmentConnector.InvoiceAttachmentService();
		ws.SessionHeader = new InvoiceAttachmentConnector.SessionHeader_element();
		ws.SessionHeader.sessionId = UserInfo.getSessionId();
		ws.handleInvoicePdfAttachment(ids);
}