Check For TextBox Value Match In Range

I am trying to have a macro to take a value from a text box and see if it is matches a value that is in a specified range. If it comes back true then it shows an error message. This code is working for text values, but if it is numeric it will not find find it.

Sub SearchForMatch()
'Procedure level declarations
Dim rngCell As Range
Dim bMatch As Boolean
' Loop through each cell in the nominated range
For Each rngCell In Range("B4:B50")
'If there us a matching value then set your
'boolean flag to true and exit the loop
If rngCell.Value = TextBox1.Value Then
bMatch = True
Exit For
End If

Next
'If a match was found then alert the user
If bMatch Then MsgBox ("Name already exsists.")
End Sub