voidsubstring(char s[ ], long start, long count, char t[ ])
{
long i,j,length=strlen(s);
if (start<1 || start>length)printf("The copy position is wrong");
else if (start+count-1>length)printf("Too characters to be copied");
else {for(i=start-1,j=0; i<start+count-1;i++,j++) t[j]=s[i]; t[j]= '\0';}
}