Open STTAD function SelectMultipleBeams does not working in vb.net

Dear Sir,

We have been trying to select multiple beam numbers in STAAD.Pro using OpenSTAAD functions.

And the .NET code is as follows,

From the above picture we can see that, list of beam numbers are loaded into one dimensional array. And the OpenSTAAD function "objOpenSTAAD.Geometry.SelectMultipleBeams(BeamNos)" does not select any beam numbers in STAAD.Pro application.