function checaForm(requiredFields)
{
    var fieldCheck   = true;
    var fieldsNeeded = "\nPor favor preencha os seguintes campos:\n\n\t";

    for(var fieldNum=0; fieldNum < requiredFields.length; fieldNum++) {
        if ((requiredFields[fieldNum].value == "") ||
            (requiredFields[fieldNum].value == " ")) {

            fieldsNeeded += requiredFields[fieldNum].name + "\n\t";
            fieldCheck = false;
        }
    }

    if (fieldCheck == true)
    {
        return true;
    }
    else
    {
        alert(fieldsNeeded);
        return false;
    }
}