Javljanje error-ja: vector subscript out of range

Napisal sem program, ki ga Compiler prevede brez napak.
Izsek programa:

#include <vector>
...
struct crta {
	CvPoint tocka1; //CvPoint je struktura z dvema parametroma int x, int y
	CvPoint tocka2;
	double kot;
	double dolzina;
	double odKI;
	double k;
	double n;
};
...
vector<crta> stranica(0);
...

void main(){
...
line[0].x = 1;
line[0].y = 1;
stranica[0].tocka1 = line[0] //v tem koraku mi program prekine in javlja error
}

Error: Program...
File:c:\program files\microsoft visual studio 8|vc\inclde\vector
Line: 756
Expression: vector subscript out of range

Za vsakrsen nasvet se vam vnaprej zahvaljujem.