By Nidal al-Mughrabi

GAZA, May 11 (Reuters) - Nine years ago, Louy al-Najar's life was changed forever by an Israeli missile that exploded as he rushed to rescue wounded neighbours during a Gaza war between Palestinian militants and Israel.

He lost both legs below the knee, a crushing blow that has not dented his spirit.

Now, aged 28, Najar has come to the aid of his neighbours again, joining them in a wheat harvest in fields near the border with Israel.

Holding a scythe, Najar crawls along the ground, out to prove, he said, that "disability is in the mind, not the body".

"I try always to make myself useful and defy my situation," said Najar, who completed a university degree a few months after his return from medical treatment in Saudi Arabia.

Najar said he is unemployed and relies on support from charities. He joined the harvest as an unpaid volunteer and hopes his efforts will draw the attention of potential employers.

"I want to give an example to people like me - they can't give up," he said. "At home I help my wife, I wash dishes, I sweep the ground and help my children with their lessons. I feel I am the happiest man in the world."

(Editing by Jeffrey Heller) ((nidal.almughrab@thomsonreuters.com; 00970599401958; Reuters Messaging: nidal.almughrabi.reuters.com@reuters.net))