Option Explicit

Solamente para eso... para que estén declaradas previamente las variables
locales.

Te adjunto el Option Explicit según MSDN:
-
Option Explicit Statement
Used at file level to force explicit declaration of all variables in that
file.
Option Explicit { On | Off }
Parts
On
Optional. Enables Option Explicit checking. If On or Off is not specified
after the Option Explicit statement, the default is On.
Off
Optional. Disables Option Explicit checking.
Remarks
If used, the Option Explicit statement must appear in a file before any
other source statements.
When Option Explicit appears in a file, you must explicitly declare all
variables using the Dim, Private, Public, or ReDim statements. If you
attempt to use an undeclared variable name, an error occurs at compile time.
If you don't use the Option Explicit statement, all undeclared variables are
of Object type.
Note Use Option Explicit to avoid incorrectly typing the name of an
existing variable or to avoid confusion in code where the scope of the
variable is not clear. If you do not specify Option Explicit in your code,
the compiler default is Option Explicit On.
Example
This example uses the Option Explicit statement to force explicit
declaration of all variables. Attempting to use an undeclared variable
causes an error at compile time. The Option Explicit statement is used at
the module level only.
Option Explicit On ' Force explicit variable declaration.
Dim MyVar As Integer ' Declare variable.
MyInt = 10 ' Undeclared variable generates error.
MyVar = 10 ' Declared variable does not generate error.


Saludos,
Jhonny Vargas P. [MS MVP]
Santiago de Chile


"Diego S." wrote in message
news:

Ademas de no poder utilizar varibles no declaradas

Que otra funcion cumple poner en todas las paginas el bendito OPTION
EXPLICIT?