Roman to Decimal(In Progress)

/* Name: James Inglis
 * Course: Data Structures and Algorithms
 * Professor: John Drugan
 * Date: 9/12/14
 * Description:
 */

#include <iostream>
#include <cstring>
#include <string>
using namespace std;

int main()
{
    float decimalForm = 0.0, total;
    int i;
    string romansNum;


    // Getting the Roman Numeral number.
    cout << "Please enter in Roman numeral characters. For example (MCXIV) : ";
    getline(cin, romansNum);
    //char store;

    total = 0.0;

    for(i = 0; i < romansNum.length(); i++)
    {
         romansNum[i];
    }


    for(i = 0; i < romansNum.length(); i++)
    {
         switch(romansNum[i])
         {
         case 'M':
             decimalForm = 1000;
             total += decimalForm;
             break;

         case 'D':
             decimalForm = 500;
             total += decimalForm;
             break;

         case 'C':
             decimalForm = 100;
             total += decimalForm;
             break;

         case 'L':
             decimalForm = 50;
             total += decimalForm;
            break;

         case 'X':
             decimalForm = 10;
             total += decimalForm;
             break;

         case 'V':
             decimalForm = 5;
             total += decimalForm;
             break;

         case 'I':
             decimalForm = 1;
             total += decimalForm;
             break;

         default:
             cerr << "Im sorry. I dont reconize that letter" << endl;
         }
    }

    cout << "The number in decimal form: " << total << endl;

    return 0;

}