Urgent C++ help!

[c++probeginner]

Please Help Me! I cannot figure out what to do. I get an error that I don't understand. I posted my code and error below:

#include <iostream>
#include <string>
#include <iomanip>
#include <cctype>

using namespace std;

//prototypes
int read_dials(char &d1, char &d2, char &d3, char &d4, char &d5, char &d6, char &d7, char &d8);
int todigits(char &d);
void acknowledge_call(char d1, char d2, char d3, char d4, char d5, char d6, char d7, char d8);


int main()
{
        int read_dials(char &d);
        char returnValue = 0;

        while (returnValue != -5)
        {
            switch (returnValue)
            {
            case -1: cout << "ERROR - An invalid character was entered." << endl; break;
            case -2: cout << "ERROR - Phone number cannot begin with 0." << endl; break;
            case -3: cout << "ERROR - Phone number cannot begin with 555." << endl; break;
            case -4: cout << "ERROR - Hyphen is not in the correct position." << endl; break;

            [COLOR="red"]default: acknowledge_call();[/COLOR]           }
        } 
        return 0;
}


int read_dials(char &d1, char &d2, char &d3, char &d4, char &d5, char &d6, char &d7, char &d8)
{
    cout << "\nEnter a phone number (Q to quit):";
    cin >> d1;
    if (d1 == 'Q')
        return -5;
    cin >> d2 >> d3 >> d4 >> d5 >> d6 >> d7 >> d8;

    // call ToDigits function
    if (todigits(d1) == -1)
        return -1;
    if (todigits(d2) == -1)
        return -1;
    if (todigits(d3) == -1)
        return -1;
    if (todigits(d5) == -1)
        return -1;
    if (todigits(d6) == -1)
        return -1;
    if (todigits(d7) == -1)
        return -1;
    if (todigits(d8) == -1)
        return -1;
    if (d4 != '-')
        return -4;
    if (d1 == 0)
        return -2;
    if (d1 && d2 && d3 == 5)
        return -3;
    else
        return 0;
}


int todigits(char &d)
{
    toupper(d);

        switch (d)
        {
            case 'A':
            case 'B':
            case 'C': d = '2'; return 0; break;
            case '1': return 0; break;
            case 'D':
            case 'E':
            case 'F': d = '3'; return 0; break;
            case '2': return 0; break;
            case 'G':
            case 'H':
            case 'I': d = '4'; return 0; break;
            case '3': return 0; break;
            case 'J':
            case 'K':
            case 'L': d = '5'; return 0; break;
            case '4': return 0; break;
            case 'M': 
            case 'N':
            case 'O': d = '6'; return 0; break;
            case '5': return 0; break;
            case 'P':
            case 'Q':
            case 'R':
            case 'S': d = '7'; return 0; break;
            case '6': return 0; break;
            case 'T':
            case 'U':
            case 'V': d = '8'; return 0; break;
            case '7': return 0; break;
            case 'W':
            case 'X':
            case 'Y':
            case 'Z': d = '9'; return 0; break;
            case '8': return 0; break;
        }
}
void acknowledge_call(char d1, char d2, char d3, char d4, char d5, char d6, char d7, char d8)
{
    cout << "Phone Number Dialed:" <<  d1 << d2 << d3 << d4 << d5 << d6 << d7 << d8 << endl;
}

Here the error message:

1>.\Lab4.cpp(28) : error C2660: 'acknowledge_call' : function does not take 0 arguments

The problem area is highlighted in red

[arkoenig]

You have defined acknowledge_call to take eight arguments. You have called it with no arguments. Hence the error message.

Next time, please use code tags.

[c++probeginner]

You have defined acknowledge_call to take eight arguments. You have called it with no arguments. Hence the error message.

Next time, please use code tags.

Sorry. I'm new to this. When I put that arguments in, I get like 3 more errors.

[arkoenig]

Please don't make us play guessing games: Show us exactly what you wrote, and tell us exactly what errors you got. And please use code tags.

[c++probeginner]

This is the section of the code where the problem is occuring.

//prototypes
int read_dials(char &d1, char &d2, char &d3, char &d4, char &d5, char &d6, char &d7, char &d8);
int todigits(char &d);
void acknowledge_call(char d1, char d2, char d3, char d4, char d5, char d6, char d7, char d8);


int main()
{
        int read_dials(char &d);
        char returnValue = 0;

        while (returnValue != -5)
        {
            switch (returnValue)
            {
            case -1: cout << "ERROR - An invalid character was entered." << endl; break;
            case -2: cout << "ERROR - Phone number cannot begin with 0." << endl; break;
            case -3: cout << "ERROR - Phone number cannot begin with 555." << endl; break;
            case -4: cout << "ERROR - Hyphen is not in the correct position." << endl; break;

            default: acknowledge_call(char d1, char d2, char d3, char d4, char d5, char d6, char d7, char d8);          }
        } 
        return 0;
}

I added code and this is the error message I now get:

1>.\Lab4.cpp(28) : error C2144: syntax error : 'char' should be preceded by ')'
1>.\Lab4.cpp(28) : error C2660: 'acknowledge_call' : function does not take 0 arguments
1>.\Lab4.cpp(28) : error C2059: syntax error : ')'

[arkoenig]

When you call a function foo with an argument x that is a variable of type char, you call it by writing foo(x) , not foo(char x) . That's your first problem.

Your next problem is that the variables d1 through d8 are not declared at the point at which you have called acknowledge_call .

And your third problem is that you are still not using code tags.