android 服务service里面出Toast

if(phoneIsInUse())
				{
					new Thread(new Runnable() {  
			            public void run() {  
			                Looper.prepare();  
			            	Toast
							.makeText(
									VuiService.this,
									"请结束通话后再试", Toast.LENGTH_LONG).show();
			                Looper.loop();  
			            }  
			        }).start();  
					return ;
				}