Write a program to calculate lenght of a given string in C language

#include<stdio.h>
#include<conio.h>  
#include<string.h>
main()
{
	char *s1;
	clrscr();
	printf("Enter string : ");
	scanf("%s",s1);
	printf("Lenght: %d",strlen(s1));
	getch();
}