Find the Lowest of These

[iiSoMeGuY 7x]

Assignment: Lowest Score Drop

This program is to calculate the average of a series of test scores, where the lowest score in the series is dropped. It should use the following functions:
*getValues should ask for 5 test scores and store them in variables. Done
*findLowest should determine which of the 5 scores is the lowest and return that value. Help!
*calcAverage should calculate and display the average of the four highest scores. Done

Input Validation: Do not accept test scores higher than 100 or lower than 0. Done
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Ok, as you can see from above, I'm mostly finished with this assignment, but I have a question about my code below (code in question is highlighted):

#include <iostream>
#include <cstdlib>
using namespace std;

int findLowest(int &, int &, int &, int &, int &);
int calcAverage(int &, int &, int &, int &, int &, int &);

int main()  //used as getValues
{
    int test1, test2, test3, test4, test5, lowest, avg;

    cout << "Please enter the score for 5 tests:\n";
    cin >> test1;
    if (test1 > 100 || test1 < 0)
    {
        system("CLS");
        cout << "Error:\nInvalid input, please try again.\n\n";
        system("PAUSE");
        system("CLS");
        return 0;
    }

    cin >> test2;
    if (test2 > 100 || test2 < 0)
    {
        system("CLS");
        cout << "Error:\nInvalid input, please try again.\n\n";
        system("PAUSE");
        system("CLS");
        return 0;
    }

    cin >> test3;
    if (test3 > 100 || test3 < 0)
    {
        system("CLS");
        cout << "Error:\nInvalid input, please try again.\n\n";
        system("PAUSE");
        system("CLS");
        return 0;
    }

    cin >> test4;
    if (test4 > 100 || test4 < 0)
    {
        system("CLS");
        cout << "Error:\nInvalid input, please try again.\n\n";
        system("PAUSE");
        system("CLS");
        return 0;
    }

    cin >> test5;
    if (test5 > 100 || test5 < 0)
    {
        system("CLS");
        cout << "Error:\nInvalid input, please try again.\n\n";
        system("PAUSE");
        system("CLS");
        return 0;
    }

    lowest = findLowest(test1, test2, test3, test4, test5);
    avg = calcAverage(test1, test2, test3, test4, test5, lowest);

    cout << "\nLowest Test Score: " << lowest << endl;
    cout << "Average of Top 4 Scores: " << avg << endl << endl;
    system("PAUSE");
    return 0;
}

//***********************************************************************************************************************************************\\
//***********************************************************************************************************************************************\\

int findLowest(int &num1, int &num2, int &num3, int &num4, int &num5)
{
    if (num1 < num2)
    {
        if (num1 < num3)
        {
            if (num1 < num4)
            {
                if (num1 < num5)
                {
                    return num1;
                }
            }
        }
    }

    else if (num2 < num1)
    {
        if (num2 < num3)
        {
            if (num2 < num4)
            {
                if (num2 < num5)
                {
                    return num2;
                }
            }
        }
    }

    else if (num3 < num1)
    {
        if (num3 < num2)
        {
            if (num3 < num4)
            {
                if (num3 < num5)
                {
                    return num3;
                }
            }
        }
    }

    else if (num4 < num1)
    {
        if (num4 < num2)
        {
            if (num4 < num3)
            {
                if (num4 < num5)
                {
                    return num4;
                }
            }
        }
    }

    else if (num5 < num1)
    {
        if (num5 < num2)
        {
            if (num5 < num3)
            {
                if (num5 < num4)
                {
                    return num5;
                }
            }
        }
    }
}

//***********************************************************************************************************************************************\\
//***********************************************************************************************************************************************\\

int calcAverage(int &num1, int &num2, int &num3, int &num4, int &num5, int &low)
{
    return (num1 + num2 + num3 + num4 + num5 - low) / 4;
}

Question: This code doesn't always give me the lowest score, after looking through it I now know why, but I can't figure out a better way to do this, can someone help me out a little please?

Thank you for your time.