Code to check first and last letter.

[ggftw]

Hi,
I have a field named CustomerNRIC and have an input mask of L0000000L. I need a code ( at OnEnter I assume ) so that when I enter the IC, the first letter must be either "S" or "T" and the last letter must be either from "A" - "J" or the letter "Z". If the user fails to do so, I will need a message box that says "Invalid ID".
Thanks.

[Seth Schrock]

I'm not sure if validation rules can do this, but you might look into Validation Rules.

Another way would be to use the control's BeforeUpdate event to check the value of the control using the Left() and Right() functions like this (This assumes that the control name on your form is CustomerNRIC):

Dim strMsg as String
Dim intFlag as Integer

intFlag = 0

If Left(Me.CustomerNRIC, 1) <> "S" or Left(Me.CustomerNRIC,1) <> "T" Then
	strMsg = "The first letter must be either S or T"
	intFlag = 1
End If

If Right(Me.CustomerNRIC, 1) <> "A" or Right(Me.CustomerNRIC, 1) <> "J" Then
	intFlag = 1
	If strMsg & "" <> "" Then
		strMsg = strMsg & VbCrLf & "and "
	End If
	strMsg = strMsg & "The last letter must be either A or J."
End If

If intFlag = 1 Then
	MsgBox strMsg
	Cancel = True
End If

[TheSmileyCoder]

I would handle this in the BeforeUpdate event of the control:

Private Sub CustomerNRIC_BeforeUpdate(Cancel as Integer)
  If nz(Me.CustomerNRIC,"")="" then 
    'Field has been cleared. Dunno whether you allow this
    Cancel=True
    Exit sub
  End if

  If left(Me.CustomerNRIC,1)<>"S" And left(Me.CustomerNRIC,1)<>"T" Then
    Msgbox "Customer NRIC must start with S or T"
    Cancel=true
    Exit Sub
  End if

  Select Case Right(Me.CustomerNRIC,1)
    Case "A","B","C","D","E","F","G","H","I","J","Z"
      'All good
    Case Else
      Msgbox "Customer NRIC must end with A-J or Z"
      Cancel=True
      Exit Sub
  End If


End Sub

[gvuksa]

Simply extract first and last letter and check condition.
Here is C# code:

private void btnEnter_Click(object sender, EventArgs e)
        {
            //Get ID to string
            string s = textBoxID.Text.ToUpper();

            //Get IDs first letter
            string firstLetter = s.Remove(1, s.Length - 1).ToUpper();

            //Check last letter
            bool lastLetter = CheckLastLetter(s.Remove(0, s.Length - 1));

            //Check if ID is correct and show error message
            if (firstLetter.Equals("T") || firstLetter.Equals("S"))
            {
                if (!lastLetter)
                    MessageBox.Show("Incorrect ID\nLast letter is incorrect");
                else
                {
                    //Login
                    MessageBox.Show("Jeeeee");
                }
            }
            else
                MessageBox.Show("Incorrect ID\nFirst letter must be \"T\" or \"S\"");
            
        }

        private bool CheckLastLetter(string lastLetter)
        {
            string[] lastLetters = new string[10] { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J" };
            foreach (string s in lastLetters)
            {
                //Compare last letter with required letter
                if (s == lastLetter)
                    return true; //Returns true if condition is satisfied
            }
            return false;            
        }

[Seth Schrock]

Oops, I missed that the last letter was A through J or Z. I just saw A or J.

[Rabbit]

@gvuksa, this is the VBA forum, not the C# forum.