Find the occurrence of given substring in given string

This program is executed from the dos shell.Input is given in the form of parameter.Two parameters are accepted as input and stored in argv.These values are then passed to variables m,c and i. The location of the substring is searched and then printed.

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

void main(int argc,char *argv[])
{
	char *i,*m,*c;
	clrscr();
	if ( argc != 3)
	{
		printf("\n Invalid arguments ");
		exit(0);
	}
	else
	{
		m=c=argv[1];
		i=argv[2];
		while(*c!='\0')
		{
			if (*m == *i)
			{
				m++;
				i++;
				if (*i=='\0')
				{
					printf("%4d",c-argv[1] +1);
					c=m;
					i=argv[2];
				}
			}
			else
			{
				c++;
				m=c;
				i=argv[2];
			}
		}
	}
} // main