c语言中用户输入的密码用*号代替，可回删

#include<stdio.h>
#include<string.h>
#include<conio.h>

void main()
{
   //char name代表用户名 mm代表登陆密码 a代表输入的密码
    char name[20], mm[3]={'y','a','n'},a[6];
    int i,g;

    printf("\n\n\n\t\t\tStudent Manager");
    for(i=0;i<3;i++)
    {    
       printf("\n\n\t\tUser Name:");
       scanf("%s",&name);

       if(strcmp(name,"grace")==0)
       { 
           printf("\t\tPlease input your password:");
           for(g=0;g<6;g++)
           {
               a[g] = getch();  /*逐次赋值,但不回显*/
               if (a[g] == '\x0d')/*回车则终止循环*/
               {
                   a[g]='\0';
                   break;
               }
               printf("*");       /*以星号代替字符个数*/
           }
           break;
       }
       else
       {
            printf("\t\tThe wrong user");

       }
   }
 }