reverse string

halo all,
i've made a program that reverses the input string.but the output is not coming right.here's my code.

Code:

#include<stdio.h>
#include<conio.h>
#include<string.h>
int main(void)
{
	char s[100];
	gets(s);
	int i;
	int len=strlen(s);
	
	for(i=0;s[i]!='\0';i++)
		s[i]=s[--len];
	puts(s);
getch();
return 0;
}

suppose i input "when"
the output comes out to be "neen" i.e it doesn't reverses the whole string.
Thanks

That's because you're creating a mirror image of the last half of the string (once you've reached the midpoint, the first half has been overwritten)! You should be swapping elements instead.