THATS TRUE COURAGE

There was a family of four, a 9 yr old daughter Lisa and a 5 yr old son Mark. Lisa was diagnosed with a rare blood disease and was predicted to die soon if the doctors did not get the cure which was some amount of blood matching their requirements likely to be found in blood relatives. Upon testing immediate relatives it was found that Mark's blood was a compatible match.
Mark was asked by his parents if he would agree to give Lisa his blood. Mark asked, "Will it save Lisa?" When they said yes he agreed. 2 days later the blood transfer began. Mark was put on a bed next to Lisa's till the blood was extracted.
After some time Mark began feeling dizzy and asked the doctors if this is the time he would start dying? The doctors were a bit amazed and it later on clicked them that Mark never knew the amount of blood required to cure Lisa, he thought all of his blood was needed and still he had reluctantly agreed to it. THATS TRUE COURAGE!!!!!