Mike703,
What you want to achieve is routine and easily doable.
However, rather than inefficiently loop through all the sheets (and there could be hundreds) doing string comparisons, try to do something with the particular sheet name you want and see if it causes an error. And, to format the sheet, do not select it - as this also is inefficient.
Code:
Sub Test()
Dim wks As Worksheet
On Error Resume Next
Set wks = Worksheets("Site Allowance")
If Err = 0 Then
With wks
' .your formatting
End With
End If
Err.Clear
Set wks = Nothing
End Sub
HTH,
Fazza