Hexadecimal to Decimal

Here's function to convert Hexadecimal number to Decimal number

/**********************************************/
/*  public long uf_Hex2Dec ( string as_Hex )  */
/**********************************************/

CONSTANT STRING ls_HexSet = "0123456789ABCDEF"

STRING  ls_Hex, ls_Bit
LONG    ll_Div, ll_RetVal = 0
INTEGER li_C, li_Len, li_Pos
BOOLEAN lb_Error = FALSE

ls_Hex = Upper( as_Hex )

IF NOT IsNull( ls_Hex ) AND ls_Hex <> "" THEN
   
    li_Len = Len( ls_Hex )
   
    FOR li_C = 1 TO li_Len
        ls_Bit = Mid( ls_Hex, li_C, 1 )
        li_Pos = Pos( ls_HexSet, ls_Bit )
       
        IF li_Pos = 0 THEN
            lb_Error = TRUE
        ELSE
            ll_RetVal += ( ( li_Pos - 1 ) * ( 16 ^ ( li_Len - li_C ) ) )
        END IF
    NEXT
    IF lb_Error THEN ll_RetVal = 0
END IF

RETURN ll_RetVal