I'm trying to create a function that sorts strings, and I've made a function that I think should work, but the `toupper()` function doesn't seem to be having any effect. Is there something I am missing here?

```
void selectionSort(string array[], int size) {
    int startScan, minIndex;
    string minValue;

    for(startScan=0; startScan<(size-1); startScan++) {
        minIndex = startScan;
        minValue = array[startScan];

        for(int index=startScan+1; index<size; index++) {
            string word = array[index];
            toupper(word[0]);
            if(array[index] < minValue) {
                minValue = array[index];
                minIndex = index;
            }
        }
        array[minIndex] = array[startScan];
        array[startScan] = minValue;
    }
}

```