如果Web服务链接不起作用，则在PHP中处理Web服务错误

I am using web services in PHP written by other developer. I want to handle error and stop the execution of next code if in case web service link is not working. I am using it first time.

       $client = new SoapClient(url,array('soap_version'=>SOAP_1_1,
            'exceptions'=>false, 
            'trace'=>1, 'login'=>"user",'password'=>"password",'connection_timeout'=>90,
            'cache_wsdl'=>WSDL_CACHE_DISK ));