I am trying to establish a macro with a message box to loop through until the
Yes button is pressed. I am using Excel 2003. My code is below:

Sub Test()
Dim PartNum As String

Do
PartNum = InputBox("Enter in Part Number:", "Part Number")
If PartNum = "" Then End
If MsgBox("The Part Number is: " & PartNum, vbYesNo) < vbYes Then
End If
Loop Until vbYesNo = vbYes

Worksheets("Sheet1").Range("H10").Value = PartNum
End Sub