谁来帮我看看这个排序二叉树怎么跑不起来？

#include<iostream>
using namespace std;
typedef int ElemType;
typedef struct TreeNode{
	ElemType data;
	struct TreeNode *l, *r;
}TreeNode, *BSTree;
void insert(BSTree *ST, int data)
{
	BSTree p;
	if(*ST == NULL)
	{
		p = new TreeNode;
		p->data = data;
		p->l = NULL;
		p->r = NULL;
		*ST = p;
	}
	else if(data<(*ST)->data)
	insert(&(*ST)->l, data);
	else if(data>(*ST)->data)
	insert(&(*ST)->r, data);
}
void view(BSTree *ST)
{
	view(&(*ST)->l);
	cout<<(*ST)->data<<" ";
	view(&(*ST)->l);
}
int main(void)
{
	int data;
	BSTree ST = NULL;
	for(int i=0; i<5; i++)
	{
		cin>>data;
		insert(&ST, data);
	}
	view(&ST);
	return 0;
}

我找了好久硬是没找出问题来。