code: function extend(a,b){
  	var c={};
  	for(var i in a){
  		if(a.hasOwnProperty(i)){
  			c[i]=a[i];
  		}
  	}
  	for(var i in b){
  		if(b.hasOwnProperty(i)){
  			c[i]=b[i];
  		}
  	}
  	return c
  }
docs: shallow object property extend