[RESOLVED] From TextBox to Listbox (Excel vb)

[DKenny]

I never use the Single datatype, I use Double instead.

OK, Here's some code that gets fired when the user click on the "Add" button. The code performs all the validations that we have identified.

I have assumed the your controls have the following names, you will need to either replace the names I have use in my code with the names of your contols, or rename your controls to the names I have used here.

My Names
txtXCoord - X textbox enter
txtYCoord - Y textbox enter
lstCoords - Listbox with Existing coordinates
cbtnAdd - Add coordinates button

There is a lot in this code, so spend some time going through it and testing it to make sure it work as you expect and that you understand exactly what it is doing at each step.
Once your happy with this section, we'll move onto the Edit record code....

Private Sub cbtnAdd_Click()
Dim dXValue As Double
Dim dYValue As Double
Dim lItemNum As Long
 
    ' ----------------------------------------------------
    ' Phase 1 - Check for Valid Data
    ' ----------------------------------------------------
    
    'Check if X Co-ord is populated
    If Me.txtXCoord.Value = "" Then
        MsgBox "Please supply a value for X."
        Me.txtXCoord.SetFocus
        Exit Sub
    End If
    
    'Check if the X Co-ord is a valid number
    If Not IsNumeric(Me.txtXCoord.Value) Then
        MsgBox "X Coordinate must be numeric."
        Me.txtXCoord.SetFocus
        Exit Sub
    End If
    
    'Check if Y Co-ord is populated
    If Me.txtYCoord.Value = "" Then
        MsgBox "Please supply a value for Y."
        Me.txtYCoord.SetFocus
        Exit Sub
    End If
    
    'Check if the Y Co-ord is a valid number
    If Not IsNumeric(Me.txtYCoord.Value) Then
        MsgBox "Y Coordinate must be numeric."
        Me.txtYCoord.SetFocus
        Exit Sub
    End If
    
    'Now that we know that we have numeric values
    'we can pass them into our variables
    dXValue = txtXCoord.Value
    dYValue = txtYCoord.Value
    
    
    ' ----------------------------------------------------
    ' Phase 2 - Check if the x value is already used
    ' ----------------------------------------------------
    
    'Loop through the existing values, trying
    'to find a match
    With Me.lstCoords
        For lItemNum = 0 To .ListCount - 1
            
            If dXValue = CDbl(.List(lItemNum, 0)) Then
                MsgBox "X Coordinate is in use."
                Me.txtXCoord.SetFocus
                Exit Sub
            End If
            
        Next lItemNum
    End With
 
    ' ----------------------------------------------------
    ' Phase 3 - Add the new values and clear the textboxes
    ' ----------------------------------------------------
    
    'Add the values to the listbox
    With Me.lstCoords
        .AddItem (dXValue)
        .Column(1, .ListCount - 1) = dYValue
    End With
    
    'Clear the Y textbox
    Me.txtYCoord.Value = ""
    
    'Clear the X textbox and move the
    'cursor to it
    With Me.txtXCoord
        .Value = ""
        .SetFocus
    End With
    
End Sub