Object对象是common的原型，Object对象的属性和方法复制到了common上
<script type="text/t">
function people(name){
this.name=name;
this.introduce=function(){ //对象方法
alert("my name is"+this.name);
}
}
people.run=function(){ //类方法
alert("i can run");
}
people.prototype.jump=function(){ //原型方法
alert("i can jump")
}
var p1=new people("vincent");
p1.introduce();
people.run(); //c#中的static
p1.jump();
</script>
function common(){
//.....
}
common.prototype=new Object();
