结构体与文件求助！！
程序代码：struct teacher
{
int num;
char *name;
char sex;
float wage;
struct teacher *next;
};
void input()
{
struct teacher tea1;
char n[20],ch;
FILE *f;
f=fopen("e:\\1.txt","wb");
if(f==NULL)
printf("can not open file");
do
{ printf("enter number:");gets(n);tea1.num=atoi(n);
printf("enter name:");gets(tea1.name);
printf("enter sex:");tea1.sex=getchar();getchar();
printf("enter wage");gets(n);tea1.wage=atof(n);
fwrite(&tea1,sizeof(struct teacher),1,f);
printf("have another teacher record(y/n)?");
ch=getchar();getchar();
}while(ch=='Y'||ch=='y');
fclose(f);
}我用结构体辅助编了个输入数据的函数 ，可是在输入第一个数据时windows就报错 弹出检查错误的窗口。但是上面的红色语句去掉后就没事了，这是怎么回事啊？
