C#

Queues: 
A queue is a "first in first out" data structure. Inserting elements is called 'enqueuing'. 
Removing/deleting elements from a queue is called 'dequeueing'. 
If you enqueue (insert) elements   in this order, then when you call dequeue, the 
first element removed is  . The second element would be   and so on. 
Input: 
Each input line will look like one of the following:
E  \n
D\n
where   is a number that will fit inside int  on the server.
Goal: 
Maintain a queue   of elements. Enqueue elements when input starts with "E". Dequeue when 
the input line is "D".
Output:
If the input line said "E  ", then enqueue (insert) the number   into  . No output!
If the input line said "D", then dequeue from   and print the number that was dequeued.
If a dequeue was requested on an empty queue, print "Empty".
Terminate all your output lines with \n .
Implementation Rules:
You must use a struct to maintain your queue. 
Use convenient typedef(s).
Create supporting functions.
Although in practice, you would create separate header file(s), we require you to put everything 
into just one .c file so that our evaluation server can be used.

public List<T> DatasettoList<T>(string commandText, CommandType commandType, IDbDataParameter[] parameters = null) where T : class, new()
        {
            DataSet dataSet = new DataSet();
            if ((commandType == null) || (commandText == null) || (commandText.Length == 0))
            {
                throw new Exception("Invailid command");
            }
            dataSet = GetDataSet(commandText, commandType, parameters);
            if (dataSet.Tables.Count == 0)
            {
                return null;
            }
            if (dataSet.Tables[0].Rows.Count == 0)
            {
                return null;
            }
            ProposalDownloadView prop = new ProposalDownloadView();
            List<ProposalDownloadView> proplist = new List<ProposalDownloadView>();
            List<T> list = new List<T>();
            var myData = dataSet.Tables[0].AsEnumerable().Select(r => new
            {
                UserId = r.Field<string>("UserId"),
                UseProposalNorId = r.Field<int>("UseProposalNorId"),
                FromDate = r.Field<decimal?>("FromDate"),
                ToDate = r.Field<decimal?>("ToDate")
            }).ToList();
            list = myData.ToList(); // this line creates the error
            return list;
        }

The below code works EXCEPT for one issue: the updated string has the following value in front of it: "System.Windows.Forms.TextBox,Text:"
Why is that there and how to be rid of it? The name of the field is masterRec. Code snippets follow:
FORM1 (main code) & FORM2 are the names I give them for purposes of this post and not their operating names. Don't think I am actually using the Get/Set apparatus.

FORM1 (In part):
FormUpdate fu = new FormUpdate(hotRec);     // INSTANTIATE UPDATE FORM CLASS
fu.action = "UP";                                                      // FormUpdate Action = UPDATE
fu.masterRec = hotRec;                                                 // Set local Master Record in FormUpdate
this.Visible = false;                                                  // Turn off visibility for this form 
fu.ShowDialog();                                                       // <--------------------------  THIS IS WHERE THE OTHER FORM EXECUTES!!!
this.Visible=true;                                                     // Turn on visibility for this form[/code]


FORM2 (In total):
namespace TestDictionary
{
    public partial class FormUpdate : Form
    {        
        //  V A R S 
       
        public string masterRec { get; set; }
        public string action { get; set; }
        private string siteId, logonID, pw, date, comments;

       // public FormUpdate()
       public FormUpdate(String myMaster)
           
        {
            InitializeComponent();
        }

        private void FormUpdate_Load(object sender, EventArgs e)    // F O R M   L O A D E D
        {
            // Disassemble the Master Record into its component fields to be displayed in this form

            if (action == "UP")
            {
                string[] tokens = masterRec.Split(',');
                siteId = tokens[0];
                logonID = tokens[1];
                pw = tokens[2];
                date = tokens[3];
                comments = tokens[4];

                websiteTextBox.Text = siteId;
                logonIDTextBox.Text = logonID;
                pwTextBox.Text = pw;
                dateTextBox.Text = date;
                commentsTextBox.Text = comments;
            }

        }

        private void Perform_Click(object sender, EventArgs e)       // P E R F O R M   B U T T O N  (AFTER UPDATES)
        {
            if (action == "UP")      // If Update, return updated Master (REASSEMBLED)
            masterRec = websiteTextBox + "," + logonIDTextBox.Text + "," + pwTextBox.Text + "," + dateTextBox.Text + "," + commentsTextBox.Text + ",";              
            this.Close();
        }
    }
}

THANK YOU FOR ANY HELP!

I have 2 projects in 1 solution. Where one of the project is included with a database manager class.

Projects

Then the second project is included with another class which have all properties of the form. That class is called Diseases class. I want store different types of diseases. Here I set the options of the input like only numbers or can't leave empty and so on.

Properties

I would to insert data from the form throw the properties class but can't see the properties class. I have a following error message:

The type or namespace name 'Diseases' could not be found (are you missing a using directive or an assembly reference?)

I'm lost. Anybody can help me please what I doing wrong?

1. The #IF symbols are ALL OVER THE CODE. It's a mess.
2. There are multiple project files that simply exist to compile different logic paths based on the symbol.