【求助】程序编译不出来？？？

#include<stdio.h>
#include<string.h>
void main()
{
    for( ; ; )
    {    
        switch(menu_selsct())
    
        { case 1:
            printf("通讯录链表的建立\n");
            break;
          case 2:
            printf("通讯者结点的插入\n");
            break;
          case 3:
            printf("通讯者结点的查询\n");
            break;
          case 4:
            printf("通讯者结点的删除\n");
            break;
          case 5:
            printf("通讯录链表的输出\n");
            break;
          case 0:
            printf("再见！\n");
            break;
           return;
        }
    }
}
int menu_select()
{
   int  sn;
   printf("通讯录管理系统\n");
   printf("****************\n");
   printf("1.通讯录链表的建立\n");
   printf("2.通讯者结点的插入\n");
   printf("3.通讯者结点的查询\n");
   printf("4.通讯者结点的删除\n");
   printf("5.通讯录链表的输出\n");
   printf("0.退出管理系统\n");
   printf("*****************\n");
   for( ; ; )
   {    scanf("%d",&sn);
        if(sn<0!!sn>5)
            printf("输入错误，重选0-5\n");
        else
            break;
    }
    return sn;
}