potty training question, please help

Hello all~

So sorry I still can't type in Chinese.  We adopted our 3rd doggie Lucky recently, a previous street astray.  As our second one was potty trained single handedly by me, I thought this one would be no problem.  But it had been 5 weeks, not much progress at all...   The doggie is very sweet and willing to learn.  But he would go potty on our carpet after an hour of outdoor play  : (.    Everyone in our family is very frustrated, especially because we are going back China for 3 weeks and we have to ask our friends to take care of the doggies... 

I potty trained the first one just by being consistent with her. Every morning 1st thing after she gets up, I would bring her to the yard and ask her to go potty, and then reward after she is done.   I used the same method with Lucky, but he seem confused exactly we are asking for... 

Any tip would be so appreciated.  Thank you all so much~  :)