Well it is good to let your employer write it for you. But i am going to present a sample of certificate for convenience. Hope it would be helpful.
EXPERIENCE CERTIFICATE
- - - - - - - - - - - - - - - - - - - - - - -
To Whom It May Concern
It is my pleasure to write on behalf of Mr. __ S/O __ who has worked with __ in capacity of Assistant Manager for six months.
During his work period Mr. __ remained involved in his work dedicatedly. I found him pretty active in whatever task I have provided him. He is a confident person. He is professionally sound, hard-working and devoted worker. He has the motivation to take initiative and I am gratified that he had been helpful in advancement of our organization.
Moreover, I would like to reflect over his conduct during his stay with us. He has a genial temperament and can efficiently work in a team. All my staff is pleased with him and feels comfortable in teaming and coordinating with him for the realization of organizational goals and objectives.
I wish him all the best in all his future endeavours.
__
General Manager
*~* I hope it will help you..
Regards
Ur's Friend :p
Salman:)