If Else statement only working for the last row of data in Excel VBA Userform - excel

Question

I'm struggling with something that sounds very simple, but there's something wrong with my code.
I have a userform with 2 textboxes when I type a 'serial number' in textbox 1, the 'RMA Number' in textbox 2 auto populates if the serial number matches an existing field in the 'RMA' column in the sheet.
If it does not match I want textbox2 to clear up or say "No Match"
I did the If-Then-Else type of code but it seems to work only for the very last entry at the moment...
What do I need to change in my code so it can match all the entries AND clear up when the Serial Number does not match??
'Autopopulate RMA# with Serial Number
Private Sub SN_TextBox1_Change()
Dim serial1_id As String
serial1_id = UCase(Trim(SN_TextBox1.Text))
lastrow = Worksheets("RMA Tracker").Cells(Rows.Count, 1).End(xlUp).Row
For i = 1 To lastrow
If UCase(Worksheets("RMA Tracker").Cells(i, 4).Value) = serial1_id Then
RMA_TextBox1.Text = Worksheets("RMA Tracker").Cells(i, 1).Value
Else
RMA_TextBox1.Value = ""
End If
Next i
End Sub

Answer 1

I think you can use Find() method to server your purpose. Below code will find TextBox1 value from RMA column (D:D). If match found then it will return value from Column A:A for matching row to TextBox2. If there is no match the it will show No Match message to TextBox2.
Private Sub CommandButton1_Click()
Dim RMA As String
Dim Rng As Range
RMA = Me.TextBox1
If Trim(RMA) <> "" Then
With Sheets("RMA Tracker").Range("D:D") 'D:D for column 4
Set Rng = .Find(What:=RMA, _
After:=.Range("A1"), _
Lookat:=xlWhole, _
LookIn:=xlFormulas, _
SearchOrder:=xlByRows, _
SearchDirection:=xlPrevious, _
MatchCase:=False)
If Not Rng Is Nothing Then
Me.TextBox2 = Rng.Offset(0, -3)
Else
Me.TextBox2 = "No Match"
End If
End With
End If
End Sub

Answer 2

Lookup Value in UserForm TextBox
To show multiple results, you have to set MultiLine to True in the properties of RMA_TextBox1.
The Code
Private Sub SN_TextBox1_Change()
Const wsName As String = "RMA Tracker"
Const FirstRow As Long = 1
Const RMACol As Variant = "A"
Const IdCol As Variant = "D"
Const IfNot As String = "No Match"
Dim wb As Workbook: Set wb = ThisWorkbook
Dim ws As Worksheet: Set ws = wb.Worksheets(wsName)
Dim LastRow As Long: LastRow = ws.Cells(ws.Rows.Count, IdCol).End(xlUp).Row
Dim SerialID As String: SerialID = Trim(SN_TextBox1.Value)
Dim i As Long, Result As String
For i = FirstRow To LastRow
If StrComp(ws.Cells(i, IdCol).Value, SerialID, vbTextCompare) = 0 Then
If Result <> "" Then
Result = Result & vbLf & ws.Cells(i, RMACol).Value
Else
Result = ws.Cells(i, RMACol).Value
End If
End If
Next i
If Result <> "" Then
RMA_TextBox1.Value = Result
Else
RMA_TextBox1.Value = IfNot
End If
End Sub