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 StringAssign(sourceaddress&, sourcelength%, destaddress&, destlength%);
 
 Usage Notes
   ■ The StringAssign syntax is for the C language. However, the order of
     arguments in the syntax follows Basic, Pascal, and FORTRAN calling
     conventions rather than the C calling convention. Note: In Basic,
     Pascal, and FORTRAN, the arguments are passed in the order in which
     they appear in the source code. In C, the arguments are passed in the
     reverse order.
 
   ■ Calls to the StringAssign routine are usually made from a C, MASM,
     Pascal, or FORTRAN routine that performs string processing functions
     on Basic strings. Seldom, if ever, do you call StringAssign from inside
     a Visual Basic program.
 
   ■ StringAssign can be used to transfer far strings. Using StringAssign,
     you can write far string independent mixed-language programs.
 
   ■ MASM, C, Pascal, and FORTRAN deal only with fixed-length strings. When
     programming in these languages you can use StringAssign to create a new
     Basic variable-length string and transfer fixed-length string data to
     it. For example, to transfer a MASM fixed-length string containing the
     word "Hello" to a Basic variable-length string, you use this data
     structure:
 
         fixedstring      db       "Hello"     ; source of data
         descriptor       dd        0          ; descriptor for destination
 
     The second data element, descriptor, is a 4-byte string descriptor
     initialized to zero. Visual Basic interprets this to mean that it should
     create a new variable-length string and associate it with the address
     labeled descriptor.
 
   ■ When creating a new variable-length string, you must allocate 4 bytes of
     static data for a string descriptor, as shown above. Allocating the data
     on the stack will not work.
 
   ■ To create a new Basic variable-length string and transfer fixed-length
     data to it, the StringAssign routine requires four arguments:
     • The far address of the fixed-length string in the MASM data segment
     • The length of the fixed-length string in the MASM data segment
     • The far address of the string descriptor in the MASM data segment
     • 0 (indicating the string in the Basic data segment will be a variable-
       length string)
 
   ■ The following MASM code pushes these arguments on the stack and calls
     StringAssign:
 
         .model
          extrn      stringassign:  far
 
         .code
          push       ds                    ; segment of fixed-length string
          lea        ax, fixedstring       ; offset of fixed-length string
          push       ax
          mov        ax, 5                 ; length of "Hello"
          push       ax
          push       ds                    ; segment of descriptor
          lea        ax, descriptor        ; offset of descriptor
          push       ax
          mov        ax, 0                 ; 0 = variable-length string
          push       ax
          call       stringassign
 
     When the call to StringAssign is made, Visual Basic fills in the double-
     word descriptor with the correct string descriptor.