Problems with error trapping using Excel macros (Visual Basic coding)

I am developing an Excel macro and am having trouble with error trapping.

Here is the actual code I am using:

'Select Name Tab

   On Error GoTo NEXTA

   Sheets(Name).Select

   GoTo NEXTB

NEXTA:

   Call Add_A_Name(Name, EnvNo)

NEXTB:

   On Error GoTo 0

The first time this code is executed, it works fine. However, the second time through the 'On Error GoTo NEXTA' statement is ignored, despite the fact that it is reset with the 'On Error GoTo 0' code. I have experienced this problem before using other logic but before, I was able to work around the problem. This time I can't. Why?