character array problem .. please help :((

Question is :
Get two strings from user. Join first string with the second string with a space. Store in another string and display it.
Example:
Enter first string: Hello
Enter second string: World
Hello World
(built in function for string concatenation is not allowed)


im newbie in c++ and arrays please tell me whats the problem in my code

Code:

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

void main()

{
clrscr();

char a[100];
char b[100];
char c[200];

int s;

cin.getline(a,100);

cin.getline(b,100);


for (s=1;c[s]!=NULL;s++)
{
c[s]=a[s]+b[s];
}


puts(c);



getch();
}

you need to use 2 loops, right now you are copying 2 characters into 1 place on the array,which you can't do.
And even if you could it would do something you don't want it to do

example of what you are doing
a= STR
b= str
proposed result of your code
SsTtRr

also array indexes start at 0 not 1

finally I don't think you can stop at NULL, rather it would be the null character '\0'

thanks for your response.. i still have a problem... in the following code it is storing a chracters not the b chracters into c.. please tell me where im wrong :

Code:

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

void main()

{clrscr();

char a[100];
char b[100];
char c[200];

int s, i;

int count=1;
int countb=0;

cin.getline(a,100);

cin.getline(b,100);



for (i=0;a[i]!='\0';i++)
{count++;}

countb=count;

for (i=0;b[i]!='\0';i++)
{countb++;}


cout<<count<<endl;

cout<<countb<<endl;


for (i=0;i<count;i++)
{c[i]=a[i];}


int r=0;

for (i=count;i<countb;i++)
{
c[i]=b[r++];
}

puts(c);

getch();
}

Code:

cout<<c[6]<<c[7];

it is displaying 2nd array..not by puts(c)

i.e cout of c[i] in loop... why not it is showing through puts?