Distance between 2 points in C++

gistfile1.txt

#include <iostream>
#include <cstdlib>
#include <cmath>

using namespace std;

// Prototypes
double Distance(double x1, double y1, double x2, double y2);

int main()
{
    // local vars
    double x1 = 4;
    double y1 = 5;
    double x2 = -4;
    double y2 = -5;
    double distance;

    distance = Distance(x1, y1, x2, y2);
    cout<<endl<<distance<<endl<<endl;

    system("pause");
    return 0;
}

/***************************************************
Function Name: Distance
Arguments: double x1, double y1, double x2, double y2
Returns: distance
***************************************************/
double Distance(double x1, double y1, double x2, double y2)
{
    double distance;

    distance = pow((pow((x2-x1), 2) + pow((y2-y1), 2)), 0.5);
    return distance;
}