void  del()
{
	FILE *fp;
	int i,j,count=0;
	char ch[2];
	char name[15];
	if((fp=fopen("data.txt","r+"))==NULL)
	{
		printf("can not open\n");
		return;
	}
	while(!feof(fp))
		if(fread(&addrinfo[count],LEN,1,fp)==1)
		count++;
		fclose(fp);
	if(count==0)
	{
		printf("no record!\n");
		return;
	}
	display();
	printf("please input the name");
	scanf("%s",&name);
	for(i=0;i<count;i++)
	{
		if(strcmp(name,addrinfo[i].name)==0)
		{
			printf("find the contact,del?(y\n)");
			scanf("%s",ch);
			if(strcmp(ch,"Y")||strcmp(ch,"y")==0)
			for(j=i;j<count;j++)//i为所需删的联系人，需将i后的联系人都前移一个位置 
			addrinfo[j]=addrinfo[j+1];
			count--;
			if((fp=fopen("data.txt","w"))==NULL)
			{
				printf("can not open");
				return;
			}for(j=0;j<count;j++)
			if(fwrite(&addrinfo[j],LEN,1,fp)!=1)
			{
				printf("can not save!\n");
				getch();
			}
			fclose(fp);
			printf("del successfully!\n");
			return;
		}
	} 
	printf("not find the contact");
}