C PROGRAMMING-- CALL BY ADDRESS ADDITION FUNCTION

#include<stdio.h>
#include<conio.h>
int add(int*,int*);
void main()
{       clrscr();
int a,b,c;
printf("enter the nos=\n");
scanf("%d\n%d",&a,&b);
c=add(&a,&b);
printf("sum=\n%d",c);
getch();
}
add(int *x,int *y)
{ int *z;
*z=*x+*y;
return *z;
}