Find Palindrome of String

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

char a[20];
int l;

int palin(int num)
{
 if(num>l/2)
  return 1;
 if(a[num] == a[l-num-1])
  return palin(num+1);
 else
  return 0;
}


void main()
{
 clrscr();
 printf("Enter a String : ");
 gets(a);
 l = strlen(a);
 int ret = palin(0);
 if(ret == 1)
  printf("\n Palindrome");
 else
  printf("\n Not Palindrome");
 getch();
}