Thread: Read a string and invert it

I'm trying to do an exercise about for, but it's not working...
The exercise says: "Make a program that inverts a string: read the string with gets and save it inverted in another string. Use the for command to scan the string up to its end."

I did this code:

Code:

#include <stdio.h>
int main()
{
    int i1,i2,t=0;
    char s1[50],s2[50];
    printf("Digite uma string: ");
    gets(s1);
    for(i1=0;s1[i1]!='\0';++i1)
    {
        ++t;
    }
    i1=0;
    for(i2=t;i2>=0;--i2)
    {
        s2[i2]=s1[i1];
        ++i1;
    }
    printf("\n\nA nova string e:\n%s",s2);
    return (0);
}

... but it doesn't work.

Could anybody, please, check my code and correct it?
Thanks a lot!