菜鸟有疑问~~读取文件搞不懂哪里出错了~

#include <iostream>
#include <stdlib.h>
using namespace std;
void main()
{
    FILE *fp;
    char ch;
    if ( (fp = fopen("kid.txt","wr+")) == NULL)
    {
        cout << "Can not open the file!" << endl;
        system("pause");
        exit(1);
    }
    cout << "Input the string :" <<endl;
    ch = getchar();
    while ( ch != '\n')
    {
        fputc(ch,fp);
        ch = getchar();
    }
    rewind(fp);                         //执行时，下列代码好像没有执行
    ch = fgetc(fp);
    while ( ch != EOF)
    {
        putchar(ch);
        ch = fgetc(fp);
    }
    fclose(fp);
}