In a sample answer , Just be YOURSELF and not any one personality , Just feel free and always thinking that you are the client and how you want to be treated , then you will for sure know the professional attitude with any client as its differ from client to another.
Support your client by meeting deadlines for his project. If you can deliver his project within the planned cost and target schedule with desired quality then you will form very good relation with your client as that is what he is looking for.
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Armia Roshdy , Director , Private Inter. Trading & Industries Co.
The relation can be maintained by :1-Customer satisfaction by supplying the required product with quality & time2-Having ( win / win ) policy relation between you as supplier & them as customer , if you face problem.