Heap Code Error - c

Question

I am getting an error in the following code. I am building a heap and for that I use the buildup and move-up functions whereas for deleting the values I use move-down and deletion functions. And for inserting the values I use insert function.
My output is showing error for the deletion part.
#include<stdio.h>
#include<stdlib.h>
int a[100];
int size;
void display();
void moveup(int);
void insert(int);
void buildup();
int deletion();
void movedown(int);
int h;
void main()
{
size=5;
int i,j;
printf("enter the elements\n");
for(i=1;i<=5;i++)
{
scanf("%d",&a[i]);
}
a[0]=32767;
printf("\n");
buildup();
display();
insert(9);
display();
printf("\n after deletion\n");
deletion();
display();
}
void buildup()
{
int i;
for(i=2;i<=size;i++)
moveup(i);
}
void moveup(int i)
{
int p,temp;
temp=a[i];
p=i/2;
while(temp>a[p])
{
a[i]=a[p];
i=p;
p=i/2;
}
a[i]=temp;
}
void display()
{
int i;
for(i=1;i<=size;i++)
printf("%3d\n",a[i]);
}
void insert(int t)
{
printf("\n after insertion\n");
if(size==99)
printf("insertion not possible");
a[++size]=t;
moveup(size);
}
int deletion()
{
int t;
t=a[1];
h=a[size--];
a[1]=h;
movedown(1);
return t;
}
void movedown(int i)
{
int l;
int r;
i=2*i;
r=l+1;
while(r<=size)
{
if(h>a[l]&&h>a[r])
{
a[i]=h;
return;
}
else
{
if(a[l]>a[r])
{
a[i]=a[l];
i=l;
}
else
{
a[i]=a[r];
i=r;
}
}
l=2*i;
r=l+1;
}
if(l<=size&&a[l]>h)
{
a[i]=a[l];
i=l;
}
a[i]=h;
}