Sub SubName [(arguments)]
  Dim [variable(s)]
  [statementblock] 
  [Exit Function]
End Sub
Declares and defines a Sub procedure name, parameters and code.  
               
               When the optional argument list needs to be passed the format is as follows:  
               ([ByVal] variable [As type] [,ByVal] variable [As type] ]…])  
               The optional ByVal parameter specifies that the variable is [passed by value instead of by reference. 
               
               
               The optional 
As Type parameter is used to specify the data type.  Valid types are String, Integer, Double, Long, and Variant. Refer to 
 Variable types for more information. 
               
               Example
Sub Main
   Dim DST As String
   DST = "t1"
   mkdir DST
   mkdir "t2"
End Sub