Calling Fortran subroutine dll from VB.NET 2010

Hi Everyone,

VB.NET

Public Declare Auto Sub MyDll Lib "MyDll.dll" (ByRef STR_IN As String, ByRef DBL_OUT As String)

Dim str as String="Praveen"

Dim str1 as String

Call MyDll(str,str1)

Fortran

subroutine MyDll(STRING_IN, DBL_OUT,strl)
IMPLICIT NONE
!DEC$ ATTRIBUTES DLLEXPORT::MyDll
!DEC$ ATTRIBUTES STDCALL,ALIAS:'MyDll' :: MyDll
CHARACTER(10), INTENT(IN) :: STRING_IN
!DEC$ ATTRIBUTES REFERENCE :: STRING_IN
CHARACTER(10), INTENT(OUT) :: DBL_OUT
DBL_OUT=STRING_IN // " A"
RETURN
end subroutine MyDll

The above code is not working and I am getting system violation exception...

Any Help Plz............

Praveen